Modern Physics CDS Questions

CDS Physics

Modern Physics MCQ Questions


7.
The total number of protons and neutrons in an atom is called:
A.
Atomic number
B.
Mass number
C.
Isotope number
D.
Atomic weight
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ANSWER :
B. Mass number
8.
Who discovered the neutron?
A.
J.J. Thomson
B.
Ernest Rutherford
C.
James Chadwick
D.
Niels Bohr
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ANSWER :
C. James Chadwick
9.

The energy of a photon is given by:

A.

E = mc2

B.

E = hλ

C.

E = hf

D.

E = 1/2 mv2

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ANSWER :

C. E = hf

10.
The photoelectric effect is based on which phenomenon?
A.
Emission of photons when light strikes a surface
B.
Emission of electrons when light strikes a surface
C.
Absorption of light by electrons
D.
Scattering of light by particles
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ANSWER :
B. Emission of electrons when light strikes a surface
11.
The stopping potential in the photoelectric effect depends on:
A.
The frequency of light
B.
The intensity of light
C.
The wavelength of light
D.
The type of material
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ANSWER :
A. The frequency of light
12.
The de Broglie wavelength of a particle is inversely proportional to its:
A.
Velocity
B.
Energy
C.
Mass
D.
Momentum
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ANSWER :
D. Momentum