(i) Iodoform is formed. Reaction Involved – PIC 1 (ii) D. D. T is condensed. Reaction Involved – PIC 1
What happens when:
How will you make (obtain) from chloroform:
(i) Acetylene
(ii) Salicylaldehyde
(i) Acetylene is obtained when chloroform is heated with silver powder. PIC (ii) Salicylaldehyde is obtained when chloroform is heated with phenol and alcoholic KOH. PIC
How will you make (obtain) from chloroform:
(i) Chloretone
(ii) Phenyl Isocyanide
(i) Chloretone is obtained from chloroform by the reaction of chloroform with acetone in the presence of base. PIC (ii) Pheny isocyanide is obtained when chloroform reacts with primary amine example...
Why does carbon mainly form covalent compounds ? .
Carbon produces compounds mostly by covalent bonding because of its small size; it cannot easily lose four electrons without expending a great deal of energy, nor can it obtain four electrons...
Write two differences between minerals and ores.
The metal is removed from the rock in a practical and cost-effective manner. Ore has a well-defined composition. Minerals are metals that exist naturally in the earth's crust. Ores are minerals that...
Explain the reasons of the followng c) Why is concave mirror used in solar cooker?
Because concave mirrors focus sunlight into a single focal point, they are employed in these types of cookers. The mirror concentrates the sun's rays onto a receiver, such as a cooking pan, in this...
Explain the reasons of the followng b) Why is convex mirror used as side mirror?
In an automobile, convex mirrors are utilised as side view mirrors to see what's behind you. Because the image generated in a convex mirror is much reduced, it provides a large field of view of...
Explain the reasons of the followng a) Why is concave mirror used as shavıng mirror? .
Because of its reflective and curved surface, concave mirrors are most typically used in shaving. When the concave mirror is held closer to the face during shaving, it creates an enlarged and erect...
Write Ohm’s law.
If all physical parameters and temperature stay constant, Ohm's law asserts that the voltage across a conductor is directly proportional to the current flowing through it. Resistance is the constant...
Distinguish between alternating current and direct current.
The magnitude of an alternating current changes with time, whereas the magnitude of a direct current remains constant. Depending on the country, the alternating current has a frequency of 50Hz or...
On what factor does the resistance of a conductor depend? The conductor’s resistance is determined by the following factors:
1.The conductor's temperature 2.The conductor's cross-sectional area 3. The conductor's length 4.The nature of the conductor's substance
Write names, formula and uses of following compounds:
(i) Luner-Caustic
(ii) Corrosive sublimate
(i) Silver nitrate (AgNO3) – Used in the preparation of laboratory reagents (ii) Mercuric Chloride (HgCl2) – Used in the making of dry cells and wood preservatives
Why is the colour of clear sky blue? .
As a result, scattered light in the sky contains a lot of blue colour, making the clear sky appear blue. Note that cities with industrial units have a greyish sky. Red, orange, and yellow colours...
What are the defects of vison ? What are its types?
Myopia is a vision impairment in which far-off things look blurred whereas items closer to the eye are perceived clearly. Hypermetropia is a vision impairment in which it is difficult to see objects...
Write names, formula and uses of following compounds:
(i) Hematite
(ii) Silver glans
(i) Iron (Fe2O3) – Used in the preparation of corrosion subatnces. (ii) Silver (Ag2S) – Used in the preparation of ornaments and vessels.
What is sphencal mirror ? What is the focal length of the spherical mirror whose radius of curvature is $20 \mathrm{~cm}$ ?
A spherical mirror is one that is cut from a spherical surface and has the shape of a portion cut out of it. Concave and convex mirrors are the two forms of spherical mirrors. $$ \begin{array}{l}...
Write four alloys of Aluminum with its names, composition and uses
(1) Duralumin – Used in the manufacture of aircraft (2) Aluminium Bronze – Used in the manufacturing of utensils and coins (3) Alloy – Used to make the parts in aircrafts (4) Magnallum Bronze – Used...
What do you understand by order of reaction? Give three examples of first order of reactions
The order of the reaction is defined as the sum of powers of active mass of reactants in rate law expression. It is an experimental value which depends on state of experiment. Examples: (i) Thermal...
What are interhalogen compounds?
The compounds that contain two distinct forms of halogens are called as interhalogen compounds. Monofluoride chlorine, trifluoride bromine, pentafluoride iode, heptafluoride iode are some of the...
Give two differences between lyophilic colloids and lyophobic colloids
What is Tyndall effect?
The occurrence of light scattering of particles in a colloid or in a fine suspension is called the tyndall effect. The particles of each suspension disperse and reflect light, making the beam...
Name in IUPAC system. ${\rm{(i)}}{{\rm{K}}_{\rm{2}}}{\rm{[PtC}}{{\rm{l}}_{\rm{6}}}{\rm{](ii)[CO(N}}{{\rm{H}}_{\rm{3}}}{{\rm{)}}_{\rm{6}}}{\rm{]C}}{{\rm{l}}_{\rm{3}}}$
IUPAC Name of K2[PtCl6] - Potassium hexachloroplatinate IUPAC Name of [CO(NH3)6]Cl3 - Hexaamminecobalt (III) chloride
Give two differences between double salt and complex salt
Give two differences between DNA and RNA
What do you understand by denaturation of protein?
Denaturation is the process by which proteins lose their shape, and their function due to changes in pH or temperature. Denaturation can easily change to a secondary, tertiary and quaternary protein...
What is the name of reactions which are initiated by the radiations?
The photochemical reaction is the name of the reaction which are initiated by the radiations
Which types of isomerism are in ${\rm{[CO(N}}{{\rm{H}}_{\rm{3}}}{{\rm{)}}_{\rm{5}}}{\rm{Br]S}}{{\rm{O}}_{\rm{4}}}{\rm{and[CO(N}}{{\rm{H}}_{\rm{3}}}{{\rm{)}}_{\rm{5}}}{\rm{S}}{{\rm{O}}_{\rm{4}}}{\rm{]Br}}$
The type of isomerism in ${\rm{[CO(N}}{{\rm{H}}_{\rm{3}}}{{\rm{)}}_{\rm{5}}}{\rm{Br]S}}{{\rm{O}}_{\rm{4}}}{\rm{and[CO(N}}{{\rm{H}}_{\rm{3}}}{{\rm{)}}_{\rm{5}}}{\rm{S}}{{\rm{O}}_{\rm{4}}}{\rm{]Br}}$...
What is the name of reaction for preparation of methyl iso cyanide?
The dehydration of N-methyl formamide is the name of reaction for preparation of methyl iso cyanide.
An adult human has teeth in mouth.
(a) 28
(b) 30
(c) 32
(d) 34
Ans. (c) 32 Explanation. A typical adult mouth has 32 teeth, all of which have erupted by the age of 13 (save for wisdom teeth): • Incisors (8 total): The upper and lower jaws' middle four teeth.
The anther contains –
(a) Sepal
(b) Ovule
(c) Carpel
(d) Pollen grains
Ans. (d) Pollen grains Explanation. Anthers are granular pods that range in colour from bright yellow to deep red and are found at the termination of filaments.
Conduction of water in algae is due to-
(a) Osmosis
(b) Diffusion
(c) Absorption
(d) Inhibition
Ans. (d) Inhibition Explanation. The process of one substance being absorbed by another, especially the uptake of water by a plant or seed.
Brain is responsible for –
(a) To think over
(b) Palpitation of heart
(c) Balance of body
(d) All
Ans. (d) All Explanation. The cerebrum is the largest region of the brain, which is a major organ of the central nervous system (CNS). The brain is supported within the skull by cerebrospinal fluid...
The number of horizontal rows in modern periodic table is
(a) 18
(b) 7
(c) 16
(d) 10
Ans. (b) 7 Explanation. In the modern periodic table, periods are the seven horizontal rows
Responsible for clotting of blood-
(a) R.B.C
(b) W.B.C
(c) Blood platelets
(d) None
Ans. (c) Blood platelets Explanation. Clotting factors, which are proteins found in your blood, send out signals to one another, causing a quick chain reaction. It culminates in the formation of...
Structural & functional unit of kidney is called
(a) Glomerulus
(b) Bowman’s capsule
(c) Urinary tube
(d) Nephron
Ans. (d) Nephron Explanation. The nephron is the kidney's basic structural and functional unit. A renal corpuscle and a renal tubule make up this tiny structure.
Which of the following is strong acid?
(a) H2SO4
(b) HCl
(c) HNO
(d) All of these
Ans. (b) HCl Explanation. There are 7 solid acids: chloric acid, hydrobromic acid, hydrochloric acid, hydroiodic acid, nitric acid, perchloric acid, and sulfuric acid.
Organic compounds which have same molecular formula but different structural formula are known as –
(a) Polymers
(b) Allotropes
(c) Isomers
(d) None of these
Ans. (c) Isomers Explanation. Organic compounds which have same molecular formula but different structural formula are known as Isomers.
The ore of mercury is –
(a) Bauxite
(b) Hematite
(c) Magnetite
(d) Cinebar
Ans. (d) Cinebar Explanation. The ore of mercury is known as "cinnabar," which is a mixture of mercury and sulphur.
What is the chemical formula of chalk?
(a) MgCO
(b) CaO
(c) CaCO
(d) CaHCO
Ans. (b) CaO Explanation. The chemical formula of chalk is CaO
The pH of an acid solution is-
(a) Equal to 7
(b) More than 7
(c) Less than 7
(d) None of these
Ans. (c) Less than 7 Explanation. Acidity is measured on a scale known as pH which sets water at 7; all acidic solutions have pH less than 7 and bases have pHs greater than 7.
Dynamo converts mechanical energy into:-
(a) Sound Energy
(b) Electrical Energy
(c) Solar Energy
(d) None of these
Ans. b) Electrical Energy Explanation. A dynamo is a device that converts mechanical energy into electrical energy.
The reason of accidents from electricity in houses is-
(a) Fuse wire
(b) Short Circuit
(c) High voltage
(d) None of these
Ans. d) None of these Explanation. Water, bad wiring, attempting to repair electricals oneself, naked wires, and damaged plugs are all typical causes of electrical accidents.
The eye is used as:-
(a) Concave mirror
(b) Conver lens
(c) Plane Mirror
(d) None of these
Ans. (d) None of these Explanation. The majority of cataract procedures in the United States are performed under local anaesthesia with IV sedation.
Which mirror is used as shaving mirror?
(a) Concave mirror
(b) Convex mirror
(c) Plane mirror
(d) None of these
Ans. (a) Concave mirror Explanation. In the instance of a shaving mirror, a concave mirror is employed because when it is put very close to the object, it magnifies it.
The reflective surface of search light is :-
(a) Convex
(b) Concave
(c) Plane
(d) None of these
Ans. (a) Convex Explanation. In a convex spherical mirror, reflection of light takes place
Which of the following is not used as a cooking fuel?
(a) C. N. G
(b) L.P. G
(c) Bio Gas
(d) Coal
Ans. (a) C. N. G Explanation. CNG is used as a clean fuel substituting gasoline.
The ray of light passes through
(a) In straight line
(b) In zig zag line
(c) In any direction
(d) None of these
(d) None of these Explanation. Because light moves from air to glass when it passes through a glass slab, it bends towards the normal because air is a rarer medium and glass is a denser media.
Draw diagram of longitudinal section of flower.
What is blood? Describe components of blood.
Erythrocytes or Red Blood Cells They convey the oxygen-transporting protein haemoglobin from the lungs to the rest of the body. Leukocytes or White Blood Cells They are basically in charge of...
What do you understand by producer?
Consumers acquire their food from producers either directly or indirectly, while producers manufacture their own food.
What is buddling?
Budding is an asexual reproduction method in which a new organism emerges from a bud or protrusion caused by cell division at a single location. A bud, for example, is a tiny bulb-like projection...
What do you understand by heterotrophic nutrition?
Because they are unable to prepare food, all animals and non-photosynthetic plants are categorised as heterotrophs. As a result, these organisms turn to alternate sources of sustenance. As a result,...
What do you understand by circulatory system?
The Components. The circulatory system is made up of numerous major components. Heart. Most people are aware of the necessity of having a healthy heart, but most are unaware that the heart has two...
What do you understand by circulatory system?
The Components. The circulatory system is made up of numerous major components. Heart. Most people are aware of the necessity of having a healthy heart, but most are unaware that the heart has two...
Write locomotory organ of Amoeba.
Pseudopodia, or fake feet, is Amoeba's locomotory organ. As a result, protoplasm streaming in amoeba is a rudimentary sort of mobility. The surface of the fake feet, or pseudopodia, forms due to the...
Describe the role of decomposers in ecosystem.
A decomposer's involvement in the environment is as follows: -To begin with, they clean the environment by decomposing dead plants and animals. -They aid in the nutrient recycling process. -By...
Write two excretory substances of human being.
Kidneys are among the organs of the human excretory system. Kidneys are bean-shaped structures that are protected by the ribs and back muscles on either side of the spine. Every single person.The...
Write the name of respiration which occurs in presence of . oxygen.
Aerobic Respiration
Write name of disease which occurs due to deficiency of vitamin A.
Ans. Eczema and other skin problems are caused due to vitamin A deficiency that leads to dry, itchy skin.
Distinguish between Metal \& Non – metal on the basis of Chemical Properties.
Ans. Non-metals aren't very durable. Their tensile strength is modest. Metals are ductile and malleable. 1. Non-metals aren't malleable or ductile in the same way as metals are. Metals are excellent...
Write down the anomalies of mendeleev’s Periodic Table.
Ans. The Mendeleev periodic table has the following flaws: Pairs that aren't supposed to be together Mendeleev's Principles are not followed by the following pairs of elements: Nickel (58.6) is...
What is Hydrogenation? What is its industrial application?
Ans. The chemical reaction between hydrogen and other molecules in the presence of a catalyst is known as hydrogenation. The process of hydrogenation is primarily used to decrease saturated...
What do you understand by catalyst?
Ans. Catalysts are chemicals that change the rate of a reaction by altering the reaction path. A catalytic reaction occurs when a catalyst is present in a system, and the phenomenon is known as...
What is replacement reaction?
Ans. A replacement reaction is a chemical reaction in which one element in a compound replaces another. A single replacement reaction or a double replacement reaction can be used to accomplish this.
Write down the atomic number of calcium.
Ans. 20
Write down the name of a non – metal which is found in liquid state at normal temperature.
Ans. Non-metal which exist as a liquid at room temperature is bromine.
Balance the following equation- CO2+H20 ?C6H12O6+H2O+O2
Ans. 6CO2+12H2O=C6H12O6 +6O2+6H20
Write down the molecular formula of Plaster of Paris.
Ans. Plaster of Paris is calcium sulphate hemihydrate. Its chemical formula is: CaSO4.21H2O.
What is Galvanisation?
Ans. Galvanization is the process of coating a metal with a protective layer of zinc. It is a standard way of protecting iron from rusting. This can be accomplished by either dipping the metal to be...
Write down the anomalies of Mendeleev’s Periodic Table.
Ans. The Mendeleev periodic table has the following flaws: Pairs that aren't supposed to be together Mendeleev's Principles are not followed by the following pairs of elements: Nickel (58.6) is...
Explain Conductor, Non – conductor, Semi – conductor and Super – conductor with example.
Ans. Materials that allow electricity to flow freely through them are referred to as electrical conductors. Conductivity is the property of conductors that allows them to conduct electricity. The...
What is Electric Generator? Explain principle of its function. Describe its structure and working procedure.
Ans. An electric generator is a device that generates electric energy that can be stored in batteries or directly delivered to homes, stores, workplaces, and other locations. Electromagnetic...
Write difference between Alterating and Direct current.
Ans. The fundamental distinction between the two is the direction in which the current flows. Direct current, also known as DC, flows in one direction uniformly, whereas alternating current, also...
What do you mean by Electric charge? Write types of Electric charge.
Ans. When matter is placed in an electromagnetic field, it acquires an electric charge, which causes it to experience a force. Positive and negative charges are the two forms of electric charge...
Write formula of relation hetween focal length and radius of curvature in concave mirror.
Ans. In both cases focal length is equal to the half of the radius of curvature. i.e, R = 2f.
What is magnification? Explain it.
Ans. Magnification is the process of enlarging something's apparent size rather than its true size. This enlargement is measured by a numerical value known as "magnification." When this value is...
Which lens is known as diverging lens?
Ans. concave lens
What is commercial unit of electrkal energy?
Ans. The commercial unit of electrical energy is kilo watt hour (kWh).
How many Laus of refraction of light are there?
At the interface of two transparent media at the point of incidence, the refracted ray, incident ray, and normal all lie in the same plane.
What are the materials used for the preparation of bleaching powder?
Materials used for the preparation of bleaching powder are calcium hydroxide and chlorine.
(a) What is the chemical name of bleaching powder? (b) What is the chemical formula of bleaching powder?
(a) The chemical name of bleaching powder is Calcium oxychloride. (b) The chemical formula of bleaching powder is $\mathrm{CaOCl}_{2}$.
Draw a diagram of a vertical section of the human brain and label the following parts. a) Cerebrum b) Cerebellum
The image represents the vertical section of the human brain. The parts cerebrum and the cerebellum is shown in the image.
Draw a labelled diagram of neuromuscular junction.
Transport of food from leaves to other parts of the plant is called _________.
Correct answer is Translocation
How is food transported in plants?
Phloem is involved in the distribution of food to different parts of the plant. The transportation of food in phloem is an active process achieved by utilizing energy from ATP which helps in...
Approximately how much large is whole digestive system in a healthy human?
The digestive system is made up of alimentary canal and other organs such as liver and pancreas. The alimentary canal is the long tube of organs including esophagus, stomach and intestines that run...
How is brain protected in our body?
The skull well protects the human brain. Inside the skull, the brain is covered by cranial meninges consisting of an outer layer called dura mater, a very thin middle layer called arachnoid and the...
The human brain weight approximately ……….% of the body weight.
The adult human brain weighs about 3 pounds (1,300-1,400 g). The adult human brain is about 2 % of the total body weight. The average human brain is 140 mm wide. So, the correct answer is 2%.
Describe the structure of human brain
The brain is made of three main parts: the forebrain, midbrain, and hindbrain. The forebrain consists of the cerebrum, thalamus, and hypothalamus. The midbrain consists of the tectum and tegmentum....
Draw a labelled diagram of human digestive system and explain it.
(i). Food is crushed and cut in the mouth with the help of teeth and is mixed with saliva that is secreted by three salivary glands(one below the tongue and two at the side of the jaw) to make it...
Distinguish between self-pollination and cross-pollination.
Pollen from the anther is deposited on the stigma of the same bloom or another flower on the same plant, resulting in self-pollination. The transfer of pollen from the anther of one flower to the...
Given reasons for adopting contraceptive methods ?
Contraceptive methods include any approach to prevent conception; for example, oral contraceptive pills, surgical methods (vasectomy, tubal ligation), contraceptive implants, diaphragm, cervical...
Name two plant hormones along with their functions.
There are several Plant Hormones classes, namely, Auxin, Cytokinin, Gibberellin, Abscisic Acid, Ethylene. Here are the functions of plant hormones in short. Functions of Auxin: Cell enlargement,...
Do you find that all living beings need the same kind of food?
No, all living beings do not need the same kind of food. They have different food requirements. Depending on their food requirements, they are classified as: 1) Herbivores: Animals that eat only...
Differentiate between autotrophic nutrition and heterotrophic nutrition ?
Autotrophs can prepare their own food because of the presence of chlorophyll within their cells. Heterotrophs can not prepare their own food due to the absence of chlorophyll, hence indirectly...
Write the steps involved in the extraction of metals from their ores.
The following are the steps involved in extracting metals from their ores: (1) Powdering of ores – Ores are crushed into small bits. With the use of a ball mill or a stamp mill, these bits are...
What are the following reactions? $$ (5 \times 1=5) $$ (i) Addition reaction (ii) Substitution reaction (iii) Esterification reaction
Sol. I Addition reactions are those in which a reactant molecule is added to another reactant molecule to generate a product. Addition reactions occur in unsaturated hydrocarbons like alkenes and...
How the electronic configuration of an atom is related to its position in the Modern Periodic table.
Sol. Electronic configuration No. of mass - period no. No. of valence - group No
Draw the structure of Benzene and Cyclohexane.
Give two ways to prevent iron from rusting.
Sol. Two ways to prevent iron from rusting (i) By painting or greasing (ii) By alloying
Why distilled water does not conduct electricity, whereas rain water does?
Sol. Distilled water does not contain any dissolved salts so it does not conduct electricity. Rain water contains dissolved impurities which are capable of conducting electricity.
Write one equation each for decomposition reaction and combination reaction.
Sol. Decomposition reaction: $\mathrm{CaCO}_{3}(\mathrm{~s}) \stackrel{\Delta}{\longrightarrow} \mathrm{CaO}(\mathrm{s})+\mathrm{CO}_{2} \uparrow$ Combination reaction : $3...
Why does the sun appear reddish early in the morning?
Ans. As the distance of travel through the atmosphere increases during dawn and dusk. Light is scattered much more than during noon. As the shorter wavelengths are scattered, only red light is left,...
What is an earth wire? What is its function?
Ans. Earth wire is a low resistance wire which connects an appliance to earth so that all the excess current passes to the earth from the wire instead of human body and hence saves from shock.
What is electric current? Write SI unit of electric current.
Ans. Electric current is the rate of change flowing through a conductor at a specific place. $$ \s\mathrm{I}=\frac{\mathrm{q}}{\mathrm{t}} $$ Ampere is the SI unit for it.
Draw a ray diagram for image of an object placed on-the principal axis of a convex mirror. Write the nature, position and size of the image formed by the mirror.
Ans. Nature - Virtual and Errect Position - B/W focus and pole. Size - Diminished
Define refractive index. The refractive index of diamond is $2.42$. What is the meaning of this statement?
Ans. A material's refractive index is a dimensionless number that describes how quickly light propagates through it. It is the ratio of the speed of light in vacuum to the speed of light in a...
Why is a normal eye not able to see clearly the objects placed closer than $25 \mathrm{~cm}$ ?
Due to the power of accommodation in the eye, a normal eye cannot see well objects that are closer than $25 mathrmcm$.
. Why do we prefer a convex mirror as a rear-view mirror in vehicles?
Ans. We utilise convex mirrors as rear-view mirrors because they provide a decreased picture and can cover a vast region.
Why is a normal eye not able to see clearly the objects placed closer than $25 \mathrm{~cm}$ ?
Ans. Due to the eye's ability to accommodate, a normal eye cannot see clearly objects that are closer than $25 mathrmcm$.
For total internal reflection to take place, the angle of incidence $i$ and the refractive index $\mu$ of the medium must satisfy the inequality
A $\frac{1}{\sin i}<\mu$
B $\frac{1}{\sin i}>\mu$
c $\operatorname{sini}<\mu$
D $\operatorname{sini}>\mu$
Correct option is A $\frac{1}{\sin i}\frac{1}{\mu}$ $$ \Rightarrow \frac{1}{\sin i}
Total internal reflection can take place only if ?
Total internal reflection can take place only if (1) Light goes from optically denser medium to rarer medium (2) Angle of incidence is greater than the critical angle
Assertion (A): Propagation of light through an optical fibre is due to total internal reflection taking place at the core-cladding interface. Reason (R) : Refractive index of the material of the core of the optical fibre is greater than that of air.
Both (A) and (R) are true but (R) is not the correct explanation of Propagation of light through an optical fibre is due to total internal reflection taking place at the interface of cable and air....
In optical fibres, propagation of light is due to which phenomenon ?
Optical fibre is a device which transmits light introduced at one end to the opposite end, with little loss of the light through the sides of the fibre. It is possible with the help of total...
Name the principle on the basis of which optical fibres work.
Optical fibres works on the principle of total internal reflection. When light ray strikes at the internal surface of optical fibre cable called such that incidence angle is greater than critical...
Name the physical principle on which the working of optical fibres is based.
The physical principle on which the working of optical fibres is based is, repeated total internal reflection of light.
Optical fiber communication is based on which of the phenomena:-
Total internal reflection
The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light:
The amount of scattering is inversely proportional to the fourth power of wavelength. And since the wavelength of red has the longest wavelength, the amount of scattering becomes smaller. Danger...
Why Red Signals are used as danger sign? Explain.
Red light is used as danger signal because it is having high wavelength, less scattering ,hence can travel larger distances.
Derive an expression for energy stored in a charged condenser. Obtain its different forms.
Let 'C' is the capacitance of the capacitor. Let 'Q' and 'V' be the charge and potential difference respectively. Let 'q' be the charge on the capacitor at some stage during charging and 'v' is the...
Derive an expression for energy stored in a capacitor. In which form energy is stored?
Let us consider a capacitor of capacitance C and potential difference V between the plates. Let the charge on one plate be +q and -q on the other. Suppose the capacitor is being charged gradually....
State the laws of refraction of light.
Incident ray, reflected ray, refracted ray and the normal of the system lie in the same plane.
What is meant by refraction of light? State the laws of refraction.
Refraction: The phenomenon of change in the direction of light when it passes from one transparent medium to another is called refraction. Laws of refraction: (i) The incident ray, the refracted ray...
Describe the reflection of light on the basis of Huygen’s wave theory.
Reflection at plane surface As shown in figure, consider a plane wavefront $A B$ incident on the plane reflecting surface AY, both the wavefront and the reflecting surface being perpendicular to the...
Explain the problem of refraction of light the basis of Huygen’s secondary wavelets theory and verify Snell’s law of refraction .
Refraction at plane Surface We will now use Huygens principle to device the laws of refraction. Let PP' represent the surface separating medium 1 and medium 2 as shown in figure 12.4. Let...
Where is the near point of a person suffering from hypermetropia (or long-sightedness)?
Hypermetropia or Long Sightedness is an eye defect. A person suffering from it can see distant objects clearly but is not able to see nearby objects clearly. The near point of a person suffering...
Complete the following sentence : (I). A short-sighted person cannot see …………… object clearly. Short-sightedness can be correct by using ……….. lenses. (II). A long-sighted person cannot see ………….. object clearly. Long-sightedness can be corrected by using ………… lenses.
(a) A short-sighted person cannot see close objects clearly. Short-sightedness can be corrected by using the concave lens in front of the eyes. (b) A long-sighted person cannot see far objects...
Write true or false for the following statements : For a person suffering from myopia, the image of the object is formed in front of the retina.
True In myopia person is not able to see far away objects due to elongation of the eyeball . The image is formed in front of the retina as shown in the figure below.
What is the far point of a person suffering from myopia (or short-sightedness)?
The far point of a person suffering from myopia or short- sightedness is less than infinity. In myopia the person is able to see close by objects clearly but they are not able to see distant objects
A person having short-sightedness cannot see objects clearly beyond a distance of 1.5 m. What would be the nature and power of the corrective lens used to restore proper vision?
Concave lens should be used to restore proper vision. Calculation of power: Object distance, $u=-\infty$ Image distance, $\mathrm{v}=-1.5 \mathrm{~m}$ $$ \begin{array}{l}...
What is short-sightedness? State the two causes of short-sightedness (or myopia)
Short Sightedness is that defect of vision due to which a person can see nearby objects clearly but cannot see distant objects clearly. Causes: 1. Excessive curvature of the eye lens 2. Elongation...
Does short-sightedness (myopia) or long-sightedness (hypermetropia) imply necessarily that the eye has partially lost its ability of accommodation? If not, what might cause these defects of vision?
The ability of the eye lens to adjust its focal length is called accommodation. No, short-sightedness (myopia) or long-sightedness (hypermetropia) does not imply necessarily that the eye has...
Long-sightedness is to hypermetropia as short-sightedness is to :
Long-sightedness is also called hypermetropia short-sightedness is also called myopia
What is a long-sighted eye ? State one cause of long-sightedness. Name the lens used for correcting long-sightedness.
An eye is said to be long-sighted if the image of a nearby object is formed behind the retina. It is caused because the eye lens cannot widen enough to reduce the focal length i.e. it is too thin or...
A man can see objects clearly up to 3m. What type of lens he should use in order to see clearly up to 12m?
Clearly, the lens used should be the concave lens. Actual far point $$ \mathrm{u}=-12 \mathrm{~m} $$ Far point of the person, $$ \mathrm{v}=-3 \mathrm{~m} $$ We have lens formula, $$...
A person suffering from myopia cannot see beyond $1 \mathrm{~m}$. What should be the focal length of the concave lens that will correct his vision?
So when the object is placed at infinity a image should be formed at $1 \mathrm{~m}$ away from eyes. So, $u=\infty$ $$ \mathrm{v}=-1 \mathrm{~m}=-100 \mathrm{~cm} $$ we know that...
Give reasons: A concave lens is used to correct myopia.
In a myopic eye, the image of a distant object is formed in front of the retina and not at the retina itself. A concave(diverging) lens causes light rays to diverge before they strike the lens of...
Which of the following lens is used to minimise myopia?
A Convex lens
B Concave lens
c Cylindrical lens
D Planar lens
Correct option is (B) Concave lens Near-sightedness, also known as short-sightedness and myopia, is a condition of the eye where light focuses in front of, instead of on, the retina. This causes...
Which of the following lens is used to correct myopia?
A Convex lens
B Concave lens
C Cylindrical lens
D None of these
Correct option is B Concave lens In Myopia, the image of a nearby object is formed ahead of the retina. By placing a concave (negative powered) lens in front of a myopic eye, the image is moved...
To remove hypermetropia lens used is –
(A) Convex
(B) Concave
(C) Cylindrical
(D) Plano-convex
Correct option is (A)Convex lens In Hypermetropia, the image of a nearby object is formed behind the retina. By placing a convex (plus powered) lens in front of a hypermetropic eye, the image is...
Write short notes on any two or the following: ii) National garden
Answer: Botanical gardens are collections of living plants that are kept for research purposes. Botanical gardens have the following functions: They provide on-site teaching opportunities regarding...
Write short notes on any two or the following: i) Greenhouse gases
Answer: The greenhouse gases in the atmosphere trap heat and warm the earth. Carbon dioxide, methane, nitrous oxide, and water vapour (all of which exist naturally) are the principal greenhouse...
Write an essay on evolution of man.
Answer: Man is the result of natural selection. As a result, human evolution is inextricably linked to the origin of life and its spread across the globe. It's common to talk about evolution in...
Comment upon DNA fingerprinting.
Answer: In genetics, DNA fingerprinting is a method of extracting and identifying variable regions within the base-pair sequence of DNA. It is also known as DNA typing, DNA profiling, genetic...
Write an essay on genetic code.
Answer: The nucleotide sequences of the mRNA determine the amino acid sequences of the protein. The genetic code, which was deciphered by Marshall Nirenberg and his colleagues in the early 1960s, is...
Comment upon any two of the following: iii) Antibody.
Answer: An antibody (Ab), also known as an immunoglobulin (Ig), is a big, Y-shaped protein that helps the immune system recognise and eliminate foreign substances like bacteria and viruses. The...
Comment upon any two of the following: ii) Bt crops
Answer: Bt Crops are transgenic plants that generate the same toxin as the Bacillus thuringiensis bacterium in the plant cell, protecting the plants from pests. The bacterium produces poisonous "cry...
Comment upon any two of the following: i) Transgenic animals
Answer: Animals (most typically mice) that have had a foreign gene purposely put into their genome are known as transgenic animals. Microinjection of DNA into the pronuclei of a fertilised egg,...
. Write notes on any two of the following iii) Plasmid.
Answer: A plasmid is a tiny extrachromosomal DNA molecule that can replicate independently of chromosomal DNA and is physically isolated from it. Plasmids are small circular double-stranded DNA...
Write notes on any two of the following : i) Hot spots
Answer: Biogeographic regions of the earth that serve as a substantial store of biodiversity but are also threatened with extinction are known as biodiversity hotspots (or biodiversity hotspots).......
Write the names of three types of RNA found in a cell and mention the function of each.
Answer: RNA types and functions. The three most well-known and studied kinds of RNA are messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA), all of which are found in all species....
Discuss the law of dominance and law of segregation propounded by Mendel.
Answer: law of segregation This legislation is founded on four fundamental ideas: • When gametes are created by meiosis, the allelic pairings split, leaving each gamete with a single allele. • For...
Describe in brief the origin of life on Earth.
Answer: Examining life on our own planet has proven to be the most fruitful strategy. However, because life began at least 3.5 billion years ago, it is difficult to trace its origins even in our own...
What is the theory of Natural selection ? Who had propounded this theory ?
Answer: Natural selection is the process through which individuals with various phenotypes survive and reproduce differently. The change in the heritable features characteristic of a population over...
Explain that phosphorus is an essential factor for biotic components of an Ecosystem. Draw a line diagram of plrosphorus cycle.
Answer: Restriction enzyme, also known as restriction endonuclease, is a bacterial protein that cleaves DNA at particular points along the molecule. Restriction enzymes cut foreign DNA in the...
Discuss the role of Biotechnology in the field of agriculture.
Answer: To defend itself against bacterial viruses known as bacteriophages, or phages, a bacterium uses a restriction enzyme. When a phage infects a bacterium, it inserts its DNA into the cell in...
Define pollution. Explain the problem of air pollution occurring in big citics of the country.
Answer: The presence of compounds in the atmosphere that are damaging to human and other living beings' health, or that damage the climate or materials, is referred to as air pollution. Gases (such...
Differentiate between the following: ii) Benign tumour (cancer) and malignant tumour (cancer).
Answer. Tumors can be benign (noncancerous) or cancerous (cancerous) (cancerous). The majority of benign tumours grow slowly and do not spread. Malignant tumours can spread throughout the body,...
Differentiate between the following: i) Innate immunity and acquired immunity
Answer: Innate immunity is an individual's inborn resistance to illnesses that he or she has from birth as a result of his or her genetic or constitutional make-up. Acquired immunity is the ability...
Write short notes on the following: ii) Fisheries.
Answer: Fishery can refer to either the business of growing or harvesting fish and other aquatic life, or the location where such business is conducted (a.k.a. fishing ground). Commercial fisheries...
Write short notes on the following: i) Role of micro-organisms in Bio. gas production
Answer: 1. During their growth, development, and metabolism, microbes produce a variety of gaseous end-products. 2. Anaerobic bacteria that grow on cellulosic materials produce huge volumes of...
Write the names of any two pathogens causing diseases in humans and comment upon their regulation.
Answer: A pathogen causes illness in its host. Pathogens are also known as infectious agents because they cause infections. Pathogens emphasise survival and reproduction, just like any other...
How does the development of endosperm take place in Angiospermic plants? Differentiate between endospermic and nonendospermic seeds with examples.
Answer:Double Fertilization When the two sperm nuclei inside a pollen particle reach the interior of a female gametophyte (also known as the embryo sac), endosperm is created. Polyploid endosperm...
Family planning is in national interest. Justify.
Answer . Through Hum Do (/humdo.nhp.gov.in/), the National Family Planning Programme seeks to provide eligible couples with information and guidance on family planning methods and services to ensure...
Draw only a line diagram of development of a female gametophyte.
What is biofortification ?
Answer: Breeding crops to boost their nutritional worth is known as biofortification. This can be accomplished using either traditional selective breeding or genetic engineering. Biofortification...
Differentiate between parasitism and commensalism.
Answer. Parasitism is a relationship between two species in which one benefits from the other and the other suffers as a result. When two species contact, one benefits while the other is neither...
Describe in brief the morphological adaptations in Hydrophytes.
Answer: The sponginess of all hydrophytes' tissues is an important anatomical trait. Their leaves, stems, and roots have a lot of air gaps in them. This aids in the maintenance of plant buoyancy and...
Define spermatogenesis
Answer: The ultimate stage of spermatogenesis is spermiogenesis. It's when spermatids turn into mature, motile spermatozoa. The nucleus, Golgi apparatus, centriole, and mitochondria are all present...
Which organigm causes the typhoid fever ?
Answer: Typhoid is a bacterial infection caused by the bacteria Salmonella typhi.
Who is called the father of Ecology in India?
Answer: At maturity, the pericarp of fleshy fruits is fleshy. There are four sorts of simple fleshy fruits. Berry, drupe, pome, and hip are the four types. One or more carpels with one or more seeds...
Write only two characteristic features of a fleshy fruit and draw the labelled diagram of a vertical section of a mango fruit.
Antibiotics are mainly obtained form i) Blue-grecn algae ii) Bacteria iii) Bryophyta iv) Viruses
Answer: ii) Bacteria Explanation- Antibiotics are chemicals that are produced by an organism and prevent the growth of other organisms. They're usually obtained from bacteria or other microbes.
Parthenogenesis occurs in i) Honeybee ii) Frog iii) Lizard iv) nonc of these.
Answer: i) Honeybee Explanation- Parthenogenesis is a reproductive method in which a female (rarely a male) gamete (sex cell) develops without being fertilised. It's most prevalent in lower plants...
In which of the following insects pollination takes place? i) Gurhal ii) Fig iii) Wheat iv) Hydrilla.
Answer: ii) Fig Explanation- The nectar provides energy while the pollen provides protein. Wasps are also important insect pollinators, pollinating many species of figs.
The most dangerous reason for the cxistence of lives is i) Desertation ii) Radiation iii) Deforestation iv) none of these.
Answer: iii) Deforestation Explanation- Because they are all connected, deforestation causes desterification, and radiation or nuclear pollution created by radioactive materials has an impact on...
Parthenogenesis occurs in i) Honeybee ii) Frog iii) Lizard iv) nonc of these.
Answer: i) Honeybee Explanation- Parthenogenesis is a reproductive method in which a female (rarely a male) gamete (sex cell) develops without being fertilised. It's most prevalent in lower plants...
In which of the following insects pollination takes place? i) Gurhal ii) Fig iii) Wheat iv) Hydrilla.
Answer: ii) Fig Explanation- The nectar provides energy while the pollen provides protein. Wasps are also important insect pollinators, pollinating many species of figs.
The most dangerous reason for the cxistence of lives is i) Desertation ii) Radiation iii) Deforestation iv) none of these.
Answer: iii) Deforestation Explanation- Because they are all connected, deforestation causes desterification, and radiation or nuclear pollution created by radioactive materials has an impact on...
Establish the laws of reflection of light on the basis of wave theory.
The reflected wave front must be built in the following manner, as shown in Figure: - I Draw an arc of a circle with a radius equal to DE from B as the centre. (ii) Draw the tangent EF to the arc...
What do you mean by $P$-type and $N$-type semiconductors ? Explain the working of a $P-N$ junction diode.
Extrinsic P-Type Semiconductors are made when a small amount of a trivalent impurity is added to a pure semiconductor, resulting in a significant number of holes. The addition of trivalent...
What is the use of a step-up transformer?
In generating stations and other power transmission applications, step up transformers are commonly utilised. The lower voltage is provided to the primary windings of power transformers at power...
What do you mean by intensity of electric field ?
The electric field is the area around an electric charge where its impact can be felt. The field of electricity The force experienced by a unit positive charge put at a certain point is called...
Explain end-on position and broad side-on position of a bar magnet.
Consider a bar magnet of length 2l and pole strength m. Suppose a point P on the axis of the magnet at a distance d from its center. (d –l) is the distance of P form the N-pole of the magnet.
What do you mean by magnetic elements of the earth ?
The magnetic declination, magnetic dip, and magnetic intensity or one of its components at any location on the earth's surface are all magnetic elements.
Write short notes on the following : v) Coenzymes of electron transport system.
Answer: Within the mitochondrial membrane, oxidative phosphorylation is a process involving the flow of electrons through the electron transport chain, a sequence of proteins, and electron carriers....
Write short notes on the following : iv) Photolysis of water
Answer: Water photolysis is the splitting of water molecules into hydrogen ions, oxygen, and electrons in the presence of light or photons. Any photon with enough energy can break any compound's...
What is the principle of conservation of charge?
The overall quantity of electric charge in a system does not change over time, according to the conservation of charge principle. Charged particles can be generated at the subatomic level, but only...
Write short notes on the following : iii) Absorption of light through chlorophyll molecules
Answer: In stage 1, light is absorbed by chlorophyll a molecules bound to reaction-center proteins in the thylakoid membrane. The energized chlorophylls donate an electron to a quinone on the...
Write short notes on the following : ii) Munch hypothesis
Answer: The best-supported explanation for explaining sap passage through the phloem is the pressure flow hypothesis, often known as the mass flow hypothesis. Ernst Münch, a German plant...
What is light year ?
A light-year is the distance light travels in one Earth year.
Write short notes on the following : i) Leghaemoglobin
Answer. Leghaemoglobin is a pigment present in the root nodules of leguminous plants that is red in colour. It mixes with oxygen and aids in the elimination of oxygen from root nodules. It aids in...
Name any four growth hormones. Draw the chemical structure of auxin and gibberellins and describe the effects of both the hormones on plants
. Answer: Many hormones required for cell growth, such as auxins, gibberellins, brassinosteroids, ethylene, jasmonates, salicylic acid, strigolactones and cytokinins which able to accelerate or...
Name any two BT crops and also write the name of chief bacteria participating in their formation.
Answer: Bt Crops are transgenic plants that generate the same toxin as the Bacillus thuringiensis bacterium in the plant cell, protecting the plants from pests. The bacterium produces poisonous "cry...
What do you mean by diffraction of light?
The small bending of light as it passes around the edge of an object is known as diffraction. The degree of bending is determined by the wavelength of light's size in relation to the opening's size....
Describe the method of transplantation of disease resistant gene in a disease infected plant.
Answer: Plant disease resistance works in two ways to defend plants from pathogens: pre-formed structures and chemicals, and immune system responses triggered by infection. [MCC No. 1] Disease...
Explain the following: ii) Acid rain
Answer: Acid rain is any type of precipitation that contains acidic components, such as sulfuric or nitric acid, that falls to the earth in wet or dry form from the atmosphere. Because power plants,...
Explain the following: i) Biochemical oxygen demand
Answer: The amount of oxygen required by bacteria and other microorganisms while decomposing organic matter under aerobic (oxygen present) conditions at a specific temperature is referred to as...
Draw labelled diagrams only of different stages of development of dicot embryo
Establish the relation between critical angle and refractive index.
A refractive index is the ratio of the velocity of a light beam in the air to the velocities of the specified medium. The critical angle is inversely proportional to the refractive index, hence the...