Photons of wavelength 4000 $A^o$ are used to break ${\mathrm{l}}_2$ molecules. The percentage of energy converted
to the kinetic energy of atoms will be:

[Given: Bond dissociation energy of the molecule is 246.5 kJ/mol]

1.  12%

2.  8%

3.  26%

4.  17%

In photoelectric effect, the kinetic energy of photoelectrons increases linearly with the:

1. Wavelength of incident light
2. Frequency of incident light
3. Velocity of incident light
4. Atomic mass of an element

Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 Å. The work function (W₀) of the metal is: 

1. 3.109 × 10^–20 J

2. 2.922 × 10^–19 J

3. 4.031 × 10¹⁹ J

4. 2.319 × 10^–18 J

The photoelectric emission from a surface starts only when the light incident upon the surface has a certain minimum:

A photon of wavelength 4 × 10^–7 m strikes a metal surface, the work function of the metal being 2.13 eV.  The kinetic energy of emission would be:

The work function of the Cesium atom is \(1.9~\mathrm{eV}.\) What is the threshold frequency of radiation for this atom?

1. 32.22 × 10^–16 J

2. 12.22 × 10^–16 J

3. 22.27 × 10^–16 J

4. 31.22 × 10^–16 J
 

A photon with an initial frequency of \(10^{11}~\mathrm{Hz}\) scatters off an electron at rest. Its final frequency is \(0.9 \times10^{11}~\mathrm{Hz}.\) The speed of scattered electron is close to: 

Calculate the work function of silver metal, given that a stopping voltage of 0.35 eV is applied and the radiation has a wavelength of 256.7 nm.

1. 3.40 eV

2. 5.18 eV

3. 4.48 eV

4. –4.40 eV

The ratio of slopes of ${\mathrm{K}}_{\max }<mspace\; width="1em"></mspace>\mathrm{vs}.<mspace\; width="1em"></mspace>\mathrm{v}<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{V}}_0<mspace\; width="1em"></mspace>\mathrm{vs}.<mspace\; width="1em"></mspace>\mathrm{v}$ curves in photoelectric effect gives -

(v=frequency, ${\mathrm{K}}_{\max }$=maximum kinetic energy, ${\mathrm{V}}_0$ stopping potential):

1.  Charge of electron

2.  Planck's constant

3.  Work function

4.  The ratio of Planck's constant of electronic charge