Please be patient as the PDF generation may take up to a minute.

A photosensitive metallic surface has work function hv₀. If photons of energy 2hv₀ falls on this surface, the electrons come out with a maximum velocity of 4 × 10⁶ m/s. When the photon energy is increased to 5hv₀, then maximum velocity of photoelectrons will be:   
1. 2 × 10⁶ m/s   
2. 2 × 10⁷ m/s  
3. 8 × 10⁷ m/s   
4. 8 × 10⁶ m/s

If the deBroglie wavelength of a proton is 1.0 × 10^–13m, the electric potential through which it must have been accelerated is
1. 4.07 × 10⁴ V                 
2. 8.2 × 10⁴ V                   
3. 8.2 × 10³ V                   
4. 4.07 × 10⁵ V

If the maximum kinetic energy of emitted photo electrons from a metal surface of work function 2.5 eV, is 1.7 eV. If wavelength of incident radiation is halved, then stopping potential will be
1.  2.5 V                                 
2.  6.7 V                               
3.  5 V                                 
4.  1.1 V

The ratio of de Broglie wavelength of $\alpha$-particle to that of a proton being subjected to the same magnetic field so that the radii of their paths are equal to each other assuming the field induction vector $\overrightarrow{\mathrm{B}}$ is perpendicular to the velocity vectors of the $\alpha$-particle and the proton is
1. 1                                           
2. 1/4                                 
3. 1/2                                   
4. 2

The energy that should be added to an electron, to reduce its de-Broglie wavelength from 10^–10 m to 0.5 × 10^–10 m, will be 
1. four times the initial energy                               
2. thrice the initial energy
3. equal to the initial energy                                   
4.  twice the initial energy  

In a photoelectric experiment, the wavelength of incident radiation is reduced from 6000Å to 4000Å then  
1. Stopping potential will decrease                        
2. Stopping potential will increase
3. Kinetic energy of emitted electrons will decrease
4. The value of work function will decrease

Figure represents the graph of kinetic energy (K) of photoelectrons (in eV) and frequency (n) for a metal used as cathode in photoelectric experiment. The work function of metal is

1. 1 eV                               
2. 1.5 eV
3. 2 eV 
4. 3 eV

The de-Broglie wavelength of a particle moving with a velocity 2.25 × 10⁸ m/s is equal to the wavelength of photon. The ratio of kinetic energy of the particle to the energy of the photon is (velocity of light is 3 × 10⁸ m/s)  
1.  1/8                                 
2.  3/8                               
3. 5/8                                   
4.  7/8

When a certain metallic surface is illuminated with monochromatic light of wavelength $\mathrm{\lambda }$, the stopping potential for photoelectric current is 3V₀. When the same surface is illuminated with the light of wavelength 2$\mathrm{\lambda }$, the stopping potential is V₀. The threshold wavelength for the surface for photoelectric effect is 
1. $\frac{4\mathrm{\lambda }}{3}$
2. $4\mathrm{\lambda }$
3. $6\mathrm{\lambda }$
4. $8\mathrm{\lambda }$

Which of the following figures represent the variation of particle momentum and the associated de-Broglie wavelength?
(a) (b) (c) (d)

An electron and a proton are separated by a large distance. The electron starts approaching the proton with energy 2eV. The proton captures the electron and forms a hydrogen atom in first excited state. The resulting photon is incident on a photosensitive metal of threshold wavelength 4600Å. The maximum K.E. of the emitted photoelectron is (Take hc = 12420 eV Å)
1. 2.4 eV                     
2. 2.7 eV                     
3. 2.9 eV                         
4. 5.4 eV

In the following diagram, the relation between $\mathrm{\lambda }$₁ and $\mathrm{\lambda }$₂ will be 

1. ${\mathrm{\lambda }}_1=\sqrt{{\mathrm{\lambda }}_2}$
2. ${\mathrm{\lambda }}_1<{\mathrm{\lambda }}_2$
3. ${\mathrm{\lambda }}_1={\mathrm{\lambda }}_2$
4. ${\mathrm{\lambda }}_1>{\mathrm{\lambda }}_2$

The ratio of de-Broglie wavelength of molecules of hydrogen and helium which are at temperatures 27°C and 127°C respectively will be 
1. $\sqrt{\frac{4}{3}}$
2. $\sqrt{\frac{8}{3}}$
3. $\sqrt{\frac{3}{8}}$
4. $\sqrt{\frac{3}{4}}$