A certain metallic surface is illuminated with monochromatic light of wavelength \(\lambda\). The stopping potential for photoelectric current for this light is \(3V_0\). If the same surface is illuminated with light of wavelength \(2\lambda\), the stopping potential is \(V_0\). The photoelectric effect's threshold wavelength for this surface is?
1. \(6\lambda\)
2. \(4\lambda\)
3. \(\dfrac{\lambda}{4}\)
4. \(\dfrac{\lambda}{6}\)

Which of the following figures represents the variation of the particle momentum and the associated de-Broglie wavelength?

1.		2.
3.		4.

What will be the percentage change in the de-Broglie wavelength of the particle if the kinetic energy of the particle is increased to \(16\) times its previous value?
1. \(25\)
2. \(75\)
3. \(60\)
4. \(50\)

For photoelectric emission from certain metal, the cut-off frequency is $\nu$. If radiation of frequency 2$\nu$ impinges on the metal plate, the maximum possible velocity of the emitted electron will be (m is the electron mass)

1. $\sqrt{h\nu /\left(2m\right)<mspace\; width="1em"></mspace>}$

2. $\sqrt{h\nu /\left(m\right)<mspace\; width="1em"></mspace>}$

3. $\sqrt{2h\nu /\left(m\right)<mspace\; width="1em"></mspace>}$

4. none of these

Photoelectric emission occurs only when the incident light has more than a certain minimum 

1. wavelength

2. intensity

3. frequency

4. power

Electrons used in an electron microscope are accelerated by a voltage of 25 kV. If the voltage is increased to 100 kV then the de-Broglie wavelength associated with the electrons would

1. decrease by 2 times

2. decrease by 4 times

3. increase by 4 times

4. increase by 2 times

The threshold frequency for a photo-sensitive metal is $3.3\times {10}^{14}<mspace\; width="1em"></mspace>\mathrm{Hz}.$ If the light of frequency $8.2\times {10}^{14}<mspace\; width="1em"></mspace>\mathrm{Hz}$ is incident on this metal, the cut-off voltage for the photo-electric emission is nearly:

1. 2 V                                        2. 3 V

3. 5 V                                         4. 1 V

An electron in the hydrogen atom jumps from nth excited state to the ground state. The wavelength so emitted illuminates a photosensitive material having work function 2.75 eV. If the stopping potential of the photo-electron is 10V, the value of n is 

(1) 3

(2) 4

(3) 5

(4) 2