Stopping Potential

Q. What is the expression of loss of kinetic energy in perfectly inelastic collision?

Q. The linear momentum of an electron, initially at rest, accelerated through a potential difference of 100 V is (in kg $m{s}^{-1}$)

1. $2.25\times {10}^7$
2. $5.4\times {10}^{-24}$
3. $5.4\times {10}^7$
4. $2.85\times {10}^{-24}$

Q.

A photoelectric cell is illuminated by a point source of light $1\mathrm{m}$ away. What happens when the source is shifted to $2\mathrm{m}$?

Q. Light of wavelength $2000\dot{A}$ falls on a metallic surface whose work function is $4.2\text{eV}$. Calculate the stopping potential. $(hc=12400\text{eV}\dot{A})$

1. $2\text{V}$
2. $3\text{V}$
3. $6\text{V}$
4. $12\text{V}$

Q. The graphs show the variation of current $I$ (y -axis) in two photocells A & B as a function of the applied voltage $V$ (x -axis), when light of same frequency is incident on the cell. Which of the following is the correct conclusion drawn from the data?

1. Cathodes of the two cells are made from the same substance, the intensity of light used are different
2. Cathodes are made from differnet substances and the intensity of light is the same
3. Cathode substances as well as intensity of ligth are different
4. No conclusion can be drawn

Q.

In a photo electric experiment 4 electrons with varying kinetic energy come out.

$E_1=1.6\times {10}^{-19}J{E}_2=2.1\times {10}^{-19}J{E}_3=3.2\times {10}^{-19}J{E}_4=1.2\times {10}^{-19}J$

The stopping potential , given this data will be Volt

Q. Will making the collector plate positive affect the saturation current?

1. Yes
2. No

Q. A beam of electromagnetic radiation of intensity 6.4$\times {10}^{-5}W/c{m}^2$ is comprised of wavelength, $\lambda =310nm$. It falls normally on a metal (work function $\varphi =2eV$) of surface area $1c{m}^2$. If one in ${10}^3$ photons ejects an electron, total number of electrons ejected in 1$s$ is ${10}^x$ ($hc=1240eV-nm,1eV=1.6\times {10}^{-19}J$), then x is

Q. What is the expression of loss of kinetic energy in perfectly inelastic collision?

Q. The equation of a light wave is written as $y=A\sin \left(kx-\omega t\right)$. Here, y represents
(a) displacement of ether particles
(b) pressure in the medium
(c) density of the medium
(d) electric field

Q. what is wave front and huygens principle?

Q. $K_{\alpha }$ wavelength emitted by an atom of atomic number $Z=11$ is $\lambda$. Find the atomic number for an atom that emits $K_{\alpha }$ radiation with wavelength $4\lambda$.

1. $Z=4$
2. $Z=11$
3. $Z=6$
4. $Z=44$