NCERT Class 12 MCQ Quiz Hub

1. De-Broglie equation states the:
dual nature
particle nature
wave nature
None of the these

2. Protons and alpha particles have the same de-Broglie wavelength. What is same for both of them ?
Energy
Time period
Frequency
Momentum

3. Kinetic energy of emitted electrons depends upon :
frequency
intensity
nature of atmosphere surrounding the electrons
None of the above

4. The ratio of specific charge of an alpha particle to the proton is:
1 : 2
2 : 1
4 : 1
1 : 4

5. In Thomson’s experiment number of parabola gives :
the no. of electrons present in element
the no. of proton present in element
the no. of neutrons present in element
the no. of isotopes of the element present

6. The work function of photoelectric material is 3.3 eV. The threshold frequency will be equal to:
8 × 1014 Hz
8 × 1010 Hz
5 × 1010 Hz
4 × 1014 Hz

7. The strength of photoelectric current depends upon :
angle of incident radiation
frequency of incident radiation
intensity of incident radiation
distance between anode and cathode

8. The momentum of an electron that emits a wavelength of 2 Å. will be:
6.4 × 10-36 kgms-1
3.3 × 10-24 kgms-1
3.3 × 10-34 kgms-1
none of these

9. Name the scientists who first studied the passage of electricity through fluids to establish the electrical nature of matter:
Millikan
Planck
Faraday
Boyle

10. Millikan’s oil drop experiment makes use of:
Stokes’ law
Boyle’s law
Gas equation
Bernoulli’s theorem

11. X-rays are:
deflected by an electric field
deflected by a magnetic field
deflected by both electric and magnetic fields
not deflected by electric and magnetic fields

12. In photo electric emission, for alkali metals the threshold frequency lies in the:
visible region
ultraviolet region
infrared region
far end of the infrared region

13. Which of the following radiations cannot eject photo electrons?
ultraviolet
infrared
visible
X-rays

14. What is the de-Broglie wavelength of an electron accelerated from rest through a potential difference of 100 volts?
12.3 Å
1.23 Å
0.123 Å
None of the these

15. When a yellow light is incident on a surface, no electrons are emitted while green light can emit electrons. If the red light is incident on the surface then:
no electrons are emitted
photons are emitted
electrons of higher energy are emitted
electrons of lower energy are emitted

16. The de-Broglie wavelength of particle of mass 1 mg moving with a velocity of 1 ms-1, in terms of Planck’s constant h, is given by (in metre):
105 h
106 h
10-3 h
103 h

17. Evidence of the wave nature of light cannot be obtained from:
diffraction
interference
doppler effect
reflection

18. which Characteristic of a target does the Mosley’s law relate the frequency of X-rays?
density
atomic number
atomic weight
interatomic space

19. Compared to liquids and solids, gases are:
good conductors of electricity
best conductors of electricity
very poor conductors of electricity
good or bad conductors of electricity depending upon the nature of the gas

20. The different stages of discharge in a discharge tube can be explained on the basis of:
the wave nature of light
the dual nature of light
wave nature of electrons
the collision between the charged particles emitted from the cathode the atoms of the gas in the tube