Answer: Because Magnesium metal combines with ambient oxygen to generate Magnesium Oxide (MgO) layer, which is a very stable chemical, it is recommended that magnesium ribbon be cleaned prior to...
Answer- Expression for power of lens (P) = 1/f We are given that P = 1.5D Therefore, f = 1/1.5 f = 10/15 So, f = 0.66 m
Answer- According to the question, Power of the lens (P) is P = -2D And the expression for the power of the lens is P = 1/f So, we get => f = -1/2 f = -0.5 m As it has a negative focal length....
Answer- According to the question, object distance (u) is – 20 cm And object height (h) is 5 cm Radius of curvature (R) is 30 cm And we know that radius of curvature = 2 × Focal length Or, R = 2f We...
Answer- A virtual and erect image generated by a flat mirror is denoted by a positive sign. The size of the image is equal to the size of the object because the magnification is 1.
Answer- According to the focal length of convex mirror, (f) is +15 cm And the object distance (u) is – 10 cm Using the mirror formula, 1/f = 1/v - 1/u Or, 1/v = 1/f + 1/u = 1/15 - 1/(-10) v = 5/30 =...
Answer- According to the question, focal length of concave lens (OF1) is f = – 15 cm Image distance (v) is – 10 cm Using the lens formula - 1/f = 1/v - 1/u Or, 1/v = 1/f + 1/u = - 1/(10) - 1/(-15)...
Answer- According to the question, height of the Object h0 is 5 cm And the distance of the object from converging lens (u) is -25 cm Also the Focal length of a converging lens is f = 10 cm...
Answer- Yes, as indicated in the illustration, it will provide a comprehensive image of the object. The image of a distant object, such as a tree. on a screen when the lower part of the lens is...
(a) Headlights of a car (b) Side/rear-view mirror of a vehicle (c) Solar furnace Support your answer with reason. Answer- (a) Concave Because when the light source is placed at their major focus,...
Answer- The object's distance from the mirror's pole ranges from 0 to 15 cm. The image's nature is virtual, upright, and larger than the thing.
(a) A convex lens of focal length 50 cm (b) A concave lens of focal length 50 cm (c) A convex lens of focal length 5 cm (d) A concave lens of focal length 5 cm Answer – The correct option is (c)....
(a) both concave (b) both convex (c) the mirror is concave and the lens is convex (d) the mirror is convex, but the lens is concave Answer – (a) Both concave The focal length of a concave mirror and...
(a) At the principal focus of the lens (b) At twice the focal length (c) At infinity (d) Between the optical centre of the lens and its principal focus. Answer – The correct option is (b). The...
(a) Between the principal focus and the centre of curvature (b) At the centre of curvature (c) Beyond the centre of curvature (d) Between the pole of the mirror and its principal focus. Answer- The...
(a) Water (b) Glass (c) Plastic (d) Clay Answer – The correct option is (d). Clay cannot be used to create a lens because light rays cannot flow through it.
Answer- According to the question, focal length of concave lens (f) is 2 m Power of lens (P) = 1/f Power = 1/ (-2) Therefore, Power = -0.5D
Answer- Because the image is actual and the same size, it should be positioned at 2F. The image of the needle is assumed to be formed at a distance of 50 cm from the convex lens. As a result, the...
Answer- The symbol D stands for dioptre, which is the SI unit of lens power. A dioptre is the power of a lens with a focal length of one metre.
Answer- Because diamond has a refractive index of 2.42, the speed of light in it is reduced by a factor of 2.42 when compared to the speed of light in air. To put it another way, the speed of light...
Material mediumRefractive indexMaterial mediumRefractiveindexAir1.0003Canada Balsam1.53Ice1.31––Water1.33Rock salt1.54Alcohol1.36––Kerosene1.44Carbon disulphide1.63Fusedquartz1.46Denseflint...
MaterialmediumRefractive indexMaterial mediumRefractiveindexAir1.0003Canada Balsam1.53Ice1.31––Water1.33Rock salt1.54Alcohol1.36––Kerosene1.44Carbon disulphide1.63Fusedquartz1.46Denseflint...
Answer- According to the question, speed of light in vacuum (c) is 3 × 108 m/s And refractive index of glass (ng) is 1.50 Expression for the speed of light in the glass (v) is given by - v = Speed...
Answer- The light ray bends in the direction of normal. When a light ray passes through an optically rarer medium (low refractive index) and enters an optically denser medium (high refractive...
Answer- Expression for magnification produced by a spherical mirror is - m = (height of image)/(height of object) Also, m = -(Image distance)/(object distance) So, we can write - (height of...
Answer- According to the question, radius of curvature (R) is 32 cm Expression for radius of curvature of the spherical mirror = 2 × Focal length (f) R = 2f Or, f= R/2 f= 32 / 2 f = 16 Therefore, 16...
Answer- In cars and vehicles, a convex mirror is favoured as a rear-view mirror. This is because it provides a broader field of view, allowing the driver to see more of the traffic behind him....
Answer- Concave Mirror is a mirror that may magnify and construct an object's image.
Answer- According to the question, radius of curvature (R) is 20 cm Expression for radius of curvature of the spherical mirror is = 2 × Focal length (f) So, R = 2f Or, f= R/2 = 20 / 2 f = 10...
Answer- After reflecting from a concave mirror, light beams that are parallel to the principal axis converge at a certain location on the principal axis. The spot is the principal focus of the...
Solution: The correct response is (b) lead acetate. Explanation: Because we need a compound that contains lead in order to obtain lead iodide, ammonium nitrate and potassium sulphate are ruled out....
Answer: option b Water contains two moles of hydrogen and one mole of water in a single mole. Because of this, the mole ratio of hydrogen to oxygen is 2:1.
Solution: Answer is option d) The elements ammonium and barium are being displaced from their respective salts, according to the data. As a result, we have a double displacement reaction. Because of...
Solution: Answer is option a) Silver halides, particularly silver chloride, decompose in the presence of sunlight, resulting in the formation of silver metal and a halogen gas (silver) (chlorine or...
Solution: The answer is (b) (ii) and (iii) In the presence of vigorous water reaction, solid calcium oxide transforms into calcium hydroxide, which is accompanied by the production of heat. This...
Solution: The answer is (b) (ii) only Sodium and barium are both displaced from their respective salts in this reaction, which is referred to as a double displacement reaction.
Solution: Answer is (a) KMnO4 is an oxidising agent, it oxidises FeSO4 Potassium permanganate (KMnO4) is used as an oxidising agent during this reaction. This is due to the presence of KMnO4, which...
Answer: Answer is (c) (i) and (iv) Exothermic processes result in the release of enormous amounts of heat – as a result, when water reacts with quick lime and when acid reacts with water, heat...
Answer: Option a) Exothermic processes result in the release of enormous amounts of heat – as a result when water reacts with quick lime and when an acid reacts with water, heat energy is...
Answer: Option c) In this reaction, oxygen reacts with water to form oxidised water. Because oxygen is being removed from water, the water's oxygen content is being reduced. Water is a source of...
Solution: Answer is (c) (i) and (iii) The reaction described here is a combination of displacement and redox reactions. The displacement reaction occurs when oxygen displaces hydrogen in ammonia,...
Answer: Answer is (d) Combustion of Liquefied Petroleum Gas (LPG) Because a new compound is formed after burning, combustion is always accompanied by a chemical change, which is irreversible in...
Answer: (c) $C_2 H_5 OH ( aq )+ CH_3 COOH (l) \longrightarrow CH_3 COO C_2 H_5( aq )+ H_2 O ( t )$It is a neutralisation reaction and double displacement reaction.(d) $C_{2} H_{4}( g )+3 O_{2}(g)...
Answer: (a) $N {2}( g )+3 H {2}( g )=\frac{\text { catalyst }}{773 K } 2 NH {2}( g )$ It is a combination reaction. (b) $NaOH ( aq )+ CH _{3} COOH ( aq ) \longrightarrow CH_3 COONa ( aq )+ H_2 O...
Answer: c) Aqueous potassium iodide solution is passed through a chlorine gas stream, resulting in the formation of potassium chloride solution and solid iodine.This is a reaction with a single...
Answer: a) Iron (III) oxide reacts with aluminium to form molten iron and aluminium oxide in the first step of the Thermit reaction. This is a reaction with a single displacement. Fe2O3 + 2Al →...
CaCO_3 (s) →xCaO(s) + CO_2 (g)$Solution: (c) Zn(s) + H2 SO4 (aq) → ZnSO4 (aq) + H2 (g) (d) CaCO3 (s) →heat→ CaO(s) + CO2 (g) x-(aq) y(g)x is heat
→
→
Answer: (a) Pb(NO3 ) 2 (aq) + 2KI(aq) → PbI2 (s) + 2KNO3 (aq) (b) Cu(s) + 2Ag NO3 (aq) → Cu(NO3 ) 2 (aq) + 2Ag(s) x(s), y (aq)x is 2Ag
Answer:An exothermic process is one that generates heat as a byproduct. A portion of this heat is transferred to the surrounding environment. Heat must be supplied to the system from the surrounding...
Answer: In a redox chemical reaction, a reducing agent is an element or compound that "donates" or "loses" an electron to an electron recipient as part of the reaction. NH3-AmmoniaH2O – Water
→
→
Answer: In a redox chemical reaction, a reducing agent is an element or compound that "donates" or "loses" an electron to an electron recipient as part of the reaction. CO-Carbon momnoxide$H_2$-...
→
→
Answer: According to chemistry, an oxidising agent, or oxidising agent, is a substance that has the ability to oxidise other substances, or to accept electrons from them, in other words, it is an...
→
→
Answer:According to chemistry, an oxidising agent, or oxidising agent, is a substance that has the ability to oxidise other substances, or to accept electrons from them, in other words, it is an...
→
→
Answer:According to chemistry, an oxidising agent, or oxidising agent, is a substance that has the ability to oxidise other substances, or to accept electrons from them, in other words, it is an...
Solution: (c) 2CuSO4+4Kl →$2K_2SO_4+Cu_2I_2+I_2$
Answer: (a) Na2CO3 + HCl → NaCl + NaHCO3 (b) NaHCO3 + HCl → NaCl + H2O + CO2
Solution: Double displacement reactions are chemical reactions in which one component of each of the reacting molecules is exchanged in order to form the products, as defined by the American...
Answer: When heated, ferrous sulfate decomposes into ferric oxide, sulphur dioxide, and sulphur trioxide, which are all toxic. Using this balanced equation, we can express the thermal decomposition...
Answer: During the course of the night, fireflies produce a chemical reaction within their bodies that allows them to glow. In the presence of an enzyme known as luciferase, oxygen reacts with...
Answer: The defense mechanism of plants prevents the fermentation of grapes on the plant. When grapes are plucked from the vine, they react with yeast to produce fermentation, which is the final...
Answer: a) Because silver is a member of the low reactive series of metals, there will be no reaction between it and dilute hydrogen chloride. b) Due to the fact that it is an exothermic reaction,...
Answer: c) Sodium is a highly reactive metal, and when it reacts with atmospheric oxygen, it produces an exothermic reaction, which raises the temperature of the surrounding environment. d) Hydrogen...
Answer: Calcium oxide is the chemical compound X. CaO is a compound that is widely used in the cement industry. Water treatment of CaO results in the formation of Ca(OH)2, which is alkaline in...
Answer: (c) Fe2O3 + 3CO + 2Fe + 3CO2 This is a redox reaction. (d) 2 H2S+O2 → 2 s + 2 H2O This is a replacement reaction.
Answer: (a) Pb(CH3COO)2 + 2HCI – PbCl2 + CH3COOH This is a Double Displacement reaction. (b) 2Na + 2C2H5OH + 2C2H5ONa+ H2 This is a Displacement reaction.
Answer: When exposed to sunlight, silver chloride decomposes into silver and chlorine gas, which are both toxic. As a result, silver chloride is stored in bottles that are dark in colour.
Answer: (c) 2Na(s) + S(s) — (Fuse) → Na2S(s) This is an example of a reaction known as a Combination reaction. (d) TiCI4 (1) + Mg(s) → Ti(s) + 2MgCl2 (s) There are several types of displacement...
Solution: (e) Cao(s) + SIO2(s) + CaSIO3(s) This reaction falls under the category of Displacement reactions (f) 2H2O2 (I) — UV → 2H2O(I) + O2 (g) This is a decomposition reaction.
(g) → 
(s) 
(g)Answer: (a) Mg(s) + Cl2(g) → MgCl2(s) A combination reaction, also known as a synthesis reaction, is a type of reaction in which two or more substances are combined. (b) 2HgO(s) — (Heat) → 2 Hg(I) +...
Solution: a) It is formed when magnesium ribbon is burned in oxygen with the emission of light and heat energy that magnesium oxide is formed.X is a compound with the chemical formula MgO. After...
Answer: Copper is more reactive than zinc because zinc is placed above hydrogen in the activity series of metals, whereas copper is placed below hydrogen in the activity series of metals. As a...
Solution: A reaction between silver and H2S in the atmosphere results in the formation of Silver Sulphide, which is a dark brown compound with a sulfuric acid smell. Corrosion is the term used to...
Answer: c) Thermal decomposition is the reaction that is taking place. d) Due to the fact that NO2 dissolves in water and forms an acidic solution, pH is less than 7. (pH range below 7).
Answer: a) b) Nitrogen dioxide, also known as $NO_2$ , is the brown gas X.
Answer: a) Pass CO2 through limewater, which will turn the water milky in colour. A confirmation test for the presence of Carbon-di-oxide is carried out here. b) The smell of SO2 is one of its...
d)
Answer: c) The oxygen test involves lighting a match stick in the presence of oxygen, which causes the match stick to burn even more brightly. d) Burning matchstick is brought close to H2 gas and...
Answer: c)There will be no reaction when silver metal is added to Copper Sulphate solution because silver is a non-reactive metal.
Solution: A) When zinc is added to a solution of copper sulfate, zinc displaces copper and forms zinc sulphate as a result. Zn(s)+ CuSo4(aq)→ ZnSo4(aq)+ Cu(s) b) When aluminium metals react with...
, HCl, 
, NaCl and NaOH, also write the chemical equations if a reaction occurs.Solution: Displacement reaction occurs when zinc granules react with concentrated H2SO4, resulting in the formation of ZnSO4 and the release of hydrogen gas. Zn( s)+ H2SO4(aq)→ ZnSo4 (aq)+H2 (g)...
Solution: c) When we add dilute $HCl$ to this reaction mixture, we get the following products: barium chloride, sulphur dioxide, and water. Due to the fact that barium chloride is a soluble...
Solution: a)The reaction of a drop of Barium Chloride solution with one drop of sodium sulphite solution results in the formation of barium sulphite, a white precipitate of barium sulphite....
, 
and 
. In which of the above containers these solutions can be kept?Answer: Due to the fact that copper is a noble metal and will not react with HCl or even $HNO_3$, it is possible to store this solution in a copper container. Keeping the solution in an aluminium...
(a) Fig. A. (b) Fig. B. (c) Fig. C. (d) Fig. D. Answer: (a) Fig. A. Explanation: The ray diagram in figure A is correct for the light ray incident on a lens as the incident ray travels through the...
(a) A (b) B (c) C (d) D Answer: b) B Explanation: The path of a ray of light coming from air passing through a rectangular glass slab traced by the student B is correct.
(a) Concave lens (b) Rectangular glass slab (c) Prism (d) Convex lens Answer: (d) Convex lens Explanation: When a beam of light is incident through the holes on side A and emerges out of the holes...
Solution: The potential difference across $4 \Omega$ resistor is potential drop by the $4 \Omega$ resistor.$V=I R=1 \times 4=4 V$The power dissipated in $4 \Omega$ resistor$$P=I^{2} R=1^{2} \times...
Solution: (a) Since, two $8 \Omega$ resistors are in parallel, then their effective resistance $R_{p}$ is given by$$\begin{aligned}\frac{1}{R_{p}}...
Solution: According to the Joules heating effect, the amount of heat that a resistor produces is For the given resistor, the voltage is directly proportional to the square of the current.Resistance...
Solution: Create a circuit with three resistors (R1, R2, and R3) connected in parallel, as shown in the diagram below: Take a reading of the potential difference between three resistors that are...
Solution: To construct the circuit, connect three resistors R1, R2, and R3 in series.Make use of an ammeter to observe the changes that have occurred in the current flow.Remove R1 and measure the...
Answer: The ability of a conductor to resist the flow of electric current is an inherent property of the conductor itself. Each material's resistance is distinct from the others. Resistance is...
Answer: Ohm’s law states that at constant temperature potential difference (voltage) across an ideal conductor is proportional to the current through it. V/I = R Ohm's law is being checked for...
Answer: a) In a series configuration, the resistance of the bulbs is three times greater than the resistance of a single bulb. As a result, when compared to the current in each bulb in the parallel...
Solution: In a parallel circuit, the potential difference does not become divided. As a result, when bulb one is fused, the glowing of the other bulbs will not be affected. 3 Amperes are being...
Solution: Evaluating the value, R= V/I = 4.5V/3A= 1.5Ω As we know that, substituting the value of parameters in P= I2R, we get = (3A)2 x 1.5 Ω = 13.5 W
Answer: Parallel wiring is commonly used in domestic wiring because it ensures that the potential difference between each electrical appliance is the same across the board.
Solution: Given: I= 1 A, V= 5 V 1) Let R be the resistance of the electric lamp. In series total resistance = 5 + R I = v/r 1 = 10/5+R R = 5 ohm 2) V across Lamp + conductor = 10 V V acoess Lamp =...
Solution: Electrical energy is a term that is used to refer to energy that has been converted from electric potential energy when it is used informally. Commercial unit of electrical energy is...
Answer: The resistivity of a conductor is defined as the property of the conductor that prevents the flow of electric current. The resistance of a particular material is one-of-a-kind. Resistance is...
Answer: The resistance of fuse wire is much higher than that of the main wiring. The electric current increases by a significant amount when this occurs. The fuse wire melts, causing the circuit to...
Solution: The circuit diagram is: The following equation can be used to calculate the total resistance of a parallel combination of 40 resistors: $\frac{1}{R}=\frac{1}{4}+\frac{1}{4}=\frac{1}{2}$$R...
Answer: The resistance of an ammeter should be low because the ammeter is connected in series with the circuit, and if the resistance of the circuit is too high, no current will flow through it.
Solution: We know that Current $P = I ^{2} R$ Evaluating the value,$$18 W = l ^{2} \times 2 \Omega \I ^{2}=18 W / 2 \Omega \ $$ =9 A I =3 AThis is the maximum current that can flow through the three...
Solution: Specifically, the ammeter has been connected in parallel with the voltmeter, which is not the correct way to connect the two metres. The ammeter should be connected in series with the...
Solution: The answer is (a) volt-ampere The apparent power of an electrical circuit is measured in volt-amperes (VA), which is the unit of measurement. A watt-second (also spelled watt-second,...
Solution: The answer is (b) same current flowing through them when connected in series When using a series combination, the current is not divided into branches because the resistor receives a...
Solution: The answer is (d) 5 A We know, P=V x I Substituting , 1000 w = 220v x I I =1000w/220v = 4.54 A = 5 A
Solution: Answer is (c) 20 J Equivalent resistance of the circuit is R = 4+2 = 6Ω current, I= V/R = 6/6= 1A the heat dissipated by 4-ohm resistor is, H = I2Rt = 20J
Solution: Answer is (c) Brightness of bulb B will be more than that of A Due to the fact that the bulbs are connected in parallel, their combined resistance will be less than the arithmetic sum of...
Solution: Answer is (c) the shape of the resistor is changed We will be re-arranging the terms we will receive, =A/RlAs a result, the resistivity of the material will be determined by its area and...
Solution: Answer is (c) 300 % The amount of heat generated by a resistor is proportional to the square of the current flowing through it. As a result, when the current is doubled, the dissipation of...
Solution: The answer is (c) R3 > R2 > R1 Resistance is inversely proportional to the amount of current flowing through it. Because the highest resistance will result in the least amount of current...
Solution: Answer is (c) 2A Explanation: We are well aware of this. R is equal to (L/A). The resistance of a wire of length L is denoted byThe area of the cross-section is denoted by the letter A.The...
Solution: The answer is a) Explanation: Electric potential is the work done per unit charge. Electric Potential=Charge Work Done Again, Charge=Current×Time...
Solution: Answer is (b) 1/25 Ω Explanation: When resistors are connected in series, the resistance is reduced to a minimum. 1/R = 5 + 5 + 5 +5 +5= 25 Ω R=1/25Ω
Solution: The answer is (a) (i) Explanation: The positive terminal of the next cell is direct across from the negative terminal of the previous cell in this arrangement.
Solution: The answer is (b) (ii) Explanation: For current to flow, an electrical circuit must be closed. An open circuit can result from improperly connected components. An ammeter measures the...
Solution: Answer is (a) 1020 Given $: I =1 A , t =16 s , e =1.6 \times 10^{-19} C$ Step 1: The filament draws current from the power supply. $I =\frac{ Q }{ t }=\frac{ Ne }{ t } \quad ($ Since $Q =...
Solution: The answer is (d) nature of the material The resistivity of a material is an inherent property of the material. As an intensive property, it does not scale with the system's size, even if...
Solution: The answer is (c) maximum in case(ii) In this example, two transistors are connected in series. Because they are connected in parallel, the total resistance in figure (iii) will be less...
Solution: The answer is (d) the same in all the cases Because there are no modifications to any of the circuits, the current in all of the circuits will be the same.
Solution: Schematic diagram showing common domestic circuits The Importance of the Fuse A fuse is a type of safety device that is used in both household wiring and electrical appliance design.The...
Solution: It is stated in Faraday's law of electromagnetic induction that whenever a conductor moves in an electromagnetic field, an electromagnetic field is induced across the conductor. If a close...
Solution: The experimental diagram of circuit is: Electromagnetic induction is a phenomenon that occurs when a magnetic field is changed in a closed circuit, resulting in the generation of an...
Solution: The schematic diagram of the simple electric motor is: A BCD coil is a coil that is placed between the two poles of a permanent magnet to create a magnetic field. The coil is positioned in...
Answer: Take a small aluminium rod (AB) and bend it in half (of about 5 cm). As shown in Fig. 1, you can suspend it horizontally from a stand by using two connecting wires. A strong horseshoe magnet...
Answer: Even in a current-carrying loop, the right-hand thumb rule is observed and followed. This demonstrates that magnetic field lines are present all around the conducting wire. However, because...
Answer: A straight conductor carrying current is held in the right hand with the thumb pointing in the direction of the current, according to the right-hand thumb rule. The fingers of the right hand...
Answer:Current carrying loops act as bar magnets with associated lines of the field, which are represented by the arrows. As a result, the existing earth's magnetic field is altered, resulting in a...
Answer: An electrical fuse is composed of a thin wire of short length that is composed of tin and lead in the proportion of 75:25 percent. When the current exceeds the specified limit, the fuse...
Answer: The direction of current in an alternating current will change constantly, whereas the direction of current in a direct current will not change. In India, the air conditioner changes...
Answer: In order to power the motor, the two conducting stationary brushes must make contact with the outer sides of the two halves of the split rings, which are both insulated and attached to the...
Answer: Fans, mixers, washing machines, and computers are just a few examples of devices in which an electric motor, a rotating device that converts electrical energy to mechanical energy, plays a...
Answer: In a current-carrying straight solenoid, the divergence of magnetic field lines near the ends indicates a decrease in the strength of the magnetic field near and beyond the ends of the...
Answer: The magnetic field strength decreases as the distance between the two points decreases. It is indicated by a decrease in the degree of closeness of the lines of field in the image.
Answer: In the right-hand rule, the thumb held by curled fingers indicates the direction of current, whereas in Fleming's left-hand rule, the force experienced by a current-carrying conductor placed...
Solution: i) Due to the fact that they are positively charged, alpha particles serve to generate current in the direction of motion. ii) Because neutrons do not have any charge on them, they do not...
Answer: As the deflection increases, so does the deflection. The strength of the magnetic field will be directly proportional to the amount of current that passes through the straight conductor, as...
Solution: P puts you into the plane of paper, and Q takes you out of it. The strength of the magnetic field is greater at the point that is closer to the source, which is Q.
Solution: It is necessary to meet the following conditions in order to obtain a permanent electromagnet from a current-carrying solenoid. Soft iron is used in a closed-circuit core.
Answer: In the plane of the paper itself, to be precise. The axis of the compass is vertical, and the magnetic field produced by the conductor is vertical as well. Because of this, it is not...
Solution: Answer is (b) use of fuse An electrical fuse is composed of a thin wire of short length that is composed of tin and lead in the proportion of 75:25 percent. When the current exceeds the...
Solution: Answer is (a) split-ring type commutator must be used After each half-turn of the armature, a split-ring type commutator reverses the direction of the current flowing through it. This...
Solution: Answer is (c) same at all points Magnetic field lines are parallel inside the solenoid. This indicates the existence of a strong magnetic field. As a result, the magnetic field is uniform...
Solution: The answer is (b) directly below the wire We can determine the direction of the magnetic field beneath the wire by applying the right-hand thumb rule.
Solution: The answer is (d) In India, the AC changes direction after every 1/50 second In India, the alternating current frequency is 50 Hz. Each cycle, the direction changes twice, so that the...
Solution: The answer is (d) there are momentary galvanometer deflections that die out shortly; the deflections are in opposite directions When the key is plugged in, the galvanometer shows...
Solution: Answer is (c) a permanent magnet to rotate the armature Electromagnets are used in place of permanent magnets in electric motors.
Solution: Answer is (a) forces both pointing into the plane of the paper Explanation: The direction of an electron's motion is the polar opposite of the direction of an electric current. This will...
Solution: Answer is (c) The pattern of the magnetic field associated with the solenoid is different from the pattern of the magnetic field around a bar magnet Because the solenoid behaves similarly...
Solution: Answer is (c) The pattern of the magnetic field associated with the solenoid is different from the pattern of the magnetic field around a bar magnet Explanation: Due to the fact that a...
Solution: Answer is (a) A Explanation: The magnetic field will be directed from the south pole to the north pole. As a result of field lines pointing from point B to point A, point A is displaying...
In the case of open magnetic field lines drawn over the horizontal plane ABCD, the magnetic field lines will take the shape of concentric circles, with the centre of each circle located at the axis...
index of medium B relative to A will be (a) greater than unity (b) less than unity (c) equal to unity (d) zero Answer: (a) greater than unity Explanation: The refractive index is the bending of a...
(a) When the object is kept at a distance equal to its radius of curvature (b) When an object is kept at a distance less than its focal length (c) When an object is placed between the focus and...
(a) – 30 cm (b) – 20 cm (c) – 40 cm (d) – 60 cm Answer: (b) – 20 cm Explanation: In this case, the focal length of the concave mirror is – 20 cm.
Answer is (c) If magnetic field lines are parallel and equidistant, they represent zero-field strength Explanation: Due to the fact that parallel lines of magnetism represent a homogenous magnetic...
Answer: When a ray of light enters a prism, it bends because of refraction of light. When the ray of light finally emerges out of the prism. it deviates drastically from its original path. This...
Answer: The sun appears red at sunrise and sunset because the sun is closer to the horizon during these times of the year. During its journey to our eyes, sunlight passes through a denser layer of...
The refraction of light through a triangular glass prism is depicted in the illustration above. At the first surface AB, a beam of light PE is penetrating the glass from the surrounding air. Due to...
Answer: Myopia is a condition in which a person's ability to see distant objects clearly is impaired. Myopia is a condition in which the image is created in front of the retina rather than behind...
Answer: The human eye is considered to be one of the most valuable and sensitive sense organs on the planet. It allows us to take in the beauty of the world and the colours that surround us. After...
Answer: The sun appears red at sunrise and sunset because the sun is closer to the horizon during these times of the year. During its journey to our eyes, sunlight passes through a denser layer of...
Answer: The colour blue is the one that scatters the most light in the visible spectrum, and it is the most intense. As a result, the blue colour is able to reach us and the sky appears to be blue.
Answer: Rainbows are generated by the dispersion of sunlight by microscopic water droplets in the atmosphere, which are present in the air. A rainbow is always generated in the opposite direction to...
Answer: When starlight enters the earth's atmosphere, it is subjected to constant refraction. Refraction happens in a material with a refractive index that is gradually changing. Starlight is...
Solution: The ray diagram is:
Solution: Using two identical prisms that are inverted with regard to one another, we can create a narrow beam of white light that is incident on one prism and emerges out of the second prism as...
Answer: Myopia is a condition in which a pupil is unable to see the chalkboard that is far away from her. As a result, the doctor recommends a concave lens with a proper focal length. Negative sign...
Solution: Myopia is a condition in which a pupil is unable to see the chalkboard that is far away from her. As a result, the doctor recommends a concave lens with a proper focal length. Answer is...
Answer: By varying the focal length of the lens, we can make our eyes focus on images from a variety of different distances. The action of the Ciliary muscle aids in the adjustment of the focal...
Myopia is a condition in which a pupil is unable to see the chalkboard that is far away from her. As a result, the doctor recommends a concave lens with a proper focal length.
Solution: Myopia is a condition in which a person's ability to see distant objects clearly outweighs his ability to perceive those closer to him. Hypermetropia is a condition in which a person...
Solution: Answer is (c) A person with myopia can see nearby objects clearly Myopia is a condition in which a person's ability to see distant objects clearly outweighs his ability to perceive those...
Solution: Answer is (a) are relaxed and the lens becomes thinner When the eye muscles relax and become thinner, the focal length of the eye lens grows in proportion to its thickness. The retina is...
Solution: The answer is (b) the outer surface of the cornea The cornea is a thin membrane that allows light to pass through to the eye. When light rays strike the cornea, they are bent inward and...
Solution: The answer is (b) reflection of sky in water Explanation: Water is colourless, but it takes on the colour of whatever it is reflected by. As a result, the sea seems blue.
Solution: The answer is (b) Scattering of light Explanation: Because red scatters the least amount of light, it may go a long distance. When the sun sets or rises, light has to travel a long...
Solution: The answer is (b) is scattered the least by smoke or fog Because the wavelength of red colour is the longest, it may be seen clearly from a long distance. It is the colour that is least...
Solution: The correct option is C All of the colours in the white light travel at the same speed as one another. Because air is not a dispersive medium, light of all wavelengths travels at the same...
Solution: The answer is (b) refraction of light by different layers of varying refractive indices Explanation: The refraction of light maintains the change in the position of the source of light....
Solution: Answer is (c) violet and blue lights get scattered more than lights of all other colors by the atmosphere. Rayleigh's scattering of sunlight is responsible for the blue appearance of the...
Solution: The answer is (b) all the colours of the white light are scattered away This is due to the dispersion of light caused by the presence of air in the environment.
Solution: Answer is (c) Refraction, dispersion, and internal reflection Dispersion of light results in the scattering of white light into multiple colours at different angles, resulting in internal...
Solution: The answer is (b) (ii) If the prism is kept with BC at the bottom, a band of colour appears at the bottom that is violet. If the prism is kept with BC at the top, violet will be at the top...
Solution: Answer is (a) The near point of his eyes has receded away In hypermetropia, the near spot of the eye is moved away for 25 cm. Thus, in order to read properly, the user needs maintain the...
Solution:The answer is (b) – 0.5 D Because the individual is myopic and in need of a concave mirror, the power would be in the negative. P=1/f=1/2m=0.5 D.
Solution: Nitrogen is the correct answer, as it possesses five electrons in its outermost shell.
Solution: Covalent bonding is formed by ammonia.
Solution: The position of sulfur is Group 16 Period 3.
Solution: 2FeSO4 Fe2O3+SO2+SO3Sulphur oxides are acidic in nature
Solution: Element X is Sulphur2,8,6
Solution: (a)The electropositive character of the element(s) increases as it progresses through the group and diminishes as it progresses through time. (b) The element's electronegativity drops as...
Solution: (a)The electropositive character of the element(s) increases as it progresses through the group and diminishes as it progresses through time. (b) The element's electronegativity drops as...
Solution: (a)The electropositive character of the element(s) increases as it progresses through the group and diminishes as it progresses through time. (b) The element's electronegativity drops as...
Solution: c) Gallium-Group 13 Period 4 is a periodic table of elements. The elements germanium and gallium are both metalloids; however, gallium is a metal. d) Germanium contains four electrons, but...
Solution: a) Eka-Silicon was replaced by germanium, while Eka-Aluminum was replaced by gallium. b) Gallium was replaced by germanium. b) Germanium-Group 14 Period 4 (Germanium-Group 14).
Solution: a) H, He, Li, Be, B, C, N, O, F, Ne, Mg, Al Si, P, S, Cl, Ar, K, Ca b) Group 1:H, Li, Na, K Group 2: Be, Mg, Ca Group 13: B. Al Group 14: C, Si Group 15: N. P Group 16: 0, S Group 17: F. U...
Solution: Across 1) Magnesium 3) Tin 4) Iodine Down 2) Sodium 5) Lithium 6) Neon 7) Astatine 8) Iron 9) Boron
Solution: (c)Nitrogen and Neon belong to period 2. Calcium and silicon belongs to Period 3. (d)Electronic Configurations Neon-2,8 Calcium-2,8,8,2 Nitrogen-2,5 Silicon-2,8,4