# Blog

### Rajasthan Board Class 12 Biology Syllabus

The RBSE (Rajasthan Board of Secondary Education) has prepared a detailed syllabus for Class 12 Biology exam of 2021-22. The syllabus is comprehensive and has been designed in such a manner that it...

### How to prepare for a Viva

How to prepare for a Viva : We all agree that exams can be scary and stressful for most of us, especially the external Viva examinations! To help ease your stress, we at Noon, wish to take you...

### Calculate the threshold frequency of photon for photoelectric emission from a metal of work function .

Ans: Given is the work function $0.1 \mathrm{eV}$, $$ \phi_{o}=h v_{0} $$ Class 12 Physics $\underline{\text { wuw. vedantu.com }}$ 1 $10 a-x=10 a-2.5 a=7.5 a$ from charge $9 q$

### What is the Brewster angle for air to glass transition? (Refractive index of glass )

Ans: We are given the refractive index of glass to be, $\mu=1.5$ BreWster angle $=\theta$ Brewster angle is known to be related to refractive index as: $$ \begin{array}{l} \tan \theta=\mu \\...

### The refractive index of glass is . What is the speed of light in glass? Speed of light in vacuum is .

Ans: Given refractive index of glass, $\mu=1.5$ Speed of light, $\mathrm{c}=3 \times 10^{8} \mathrm{~m} / \mathrm{s}$ Now, we have the speed of light in glass given by the relation, $$...

### Consider interference between two sources of intensities I and 4I. What will be the intensity at points where phase differences are:

Ans: We know that, $I=a^{2}+b^{2}+2 a b \cos \phi$ Where, $a$ and $b$ are amplitudes of two coherent waves that are having phase difference of $\phi$. Here $a^{2}=I, b^{2}=41$ $$ \begin{array}{l}...

### Write two points of difference between interference and diffraction.

Ans: Some differences between interference and diffraction are the following: \begin{tabular}{|l|l|} \hline \multicolumn{1}{|c|}{ Interference } & \multicolumn{1}{c|}{ Diffraction } \\ \hline...

### At a certain location in Africa, a compass points west of the geographic north. The north tip of the magnetic needle of a dip circle placed in the plane of magnetic meridian points above the horizontal. The horizontal component of the earth’s field is measured to be Specify the direction and magnitude of the earth’s field at the location.At a certain location in Africa, a compass points west of the geographic north. The north tip of the magnetic needle of a dip circle placed in the plane of magnetic meridian points above the horizontal. The horizontal component of the earth’s field is measured to be Specify the direction and magnitude of the earth’s field at the location.

Ans: In the above question it is given that: Angle of declination, $\theta=12^{\circ}$ Angle of dip, $\delta=60^{\circ}$ Horizontal component of earth's magnetic field, $B_{H}=0.16 \mathrm{G}$...

### Two long and parallel straight wires and carrying currents of and in the same direction are separated by a distance of . Estimate the force on a section of wire A.

Ans: We are given the following: Current flowing in wire $A_{1} I_{A}=8.0 \mathrm{~A}$ Current flowing in wire $B, I_{B}=5.0 \mathrm{~A}$ Distance between the two wires, $r=4.0 \mathrm{~cm}=0.04...

### A wire carrying a current of is placed inside a solenoid perpendicular to its axis. The magnetic field inside the solenoid is given to be . What is the magnetic force on the wire?

Ans: We are given the following: Length of the wire, $I=3 \mathrm{~cm}=0.03 \mathrm{~m}$ Current flowing in the wire, $1=10 \mathrm{~A}$. Magnetic field, $B=0.27 \mathrm{~T}$ Angle between the...

### What is the magnitude of magnetic force per unit length on a wire carrying a current of and making an angle of with the direction of a uniform magnetic field of

Ans: We are given the following: Current in the wire, $I=8 \mathrm{~A}$ Magnitude of the uniform magnetic field, $B=0.15 \mathrm{~T}$ Angle between the wire and magnetic field, $\theta=30^{\circ}$...

### A long straight wire carries a current of . What is the magnitude of the field at a point from the wire?

Ans: We are given the following: Current in the wire, $\mathrm{I}=35 \mathrm{~A}$ Distance of a point from the wire, $r=20 \mathrm{~cm}=0.2 \mathrm{~m}$ Magnitude of the magnetic field at this point...