11. The energy of a photon of frequency f is given by E= hf, where h is Plank’s constant. The momentum of a photon of wavelength  is p  ℎ/ . Then we may conclude that velocity of light is equal to:

A. (E/P) ^1⁄2                                                                                  
B. (E/P)

      
C. Ep                                                                          
D. (E/P)^2   
 

12. If the value of h is 6.6 1034 J s, the energy of a quantum of frequency 1015 Hz will be:

A. 6.61019 J                                                                                  B. 6.61012 J  
       
C. 6.61049 J                                                  
D. 6.61041 J
 

13. If stopping potential is 3 volts. The maximum K.E of photoelectron is:

A. 1.6×10-19 J                                             
B. 3.2×10-19 J
C. 4.8×10-19 J                                                
D. 6.4×10-19 J
 

14. K.Emax of photoelectrons depends upon.

A. Intensity of light                                   
B. Frequency of light
C. Energy of light                                     
D. Both B and C
    

 

15. If work function for a surface is ℎ/2 then photoelectric threshold frequency is (where h is plank’s constant)

A. 1 Hz                                                          
B. 0.5 Hz
                        
C. 1.5 Hz                                                       
D. 2 Hz
 

16. Which cathode material emits photoelectrons for white light?

A. Potassium cathode
       
B. Cesium coated oxidized silver cathode
       
C. Both A and B
       
D. Aluminum cathode
 

17. A brighter light as compared to a dimmer light of same colour will eject:

A. More number of electrons                    
B. Less number of electrons
      
C. Electrons of greater K.E                           
D. Electrons of lesser K.E
 

18. The rest mass of photon is:

A. Zero                                                             
B. Infinite
     
C. Finite                                                              
D. Constant
 

19. The absorption power of perfect black body is:

A. Equal to 1                                                  
B. Less than 1
        
C. Greater than 1                                             
D. None of these
 

20. Which of the following equation represent Einstein’s equation of photoelectric effect K.E max=?effect K.E max=??

A. hf                                                                    
B. h(f + fo)
       
C. hfo                                                                    
D. h(f - fo)