JEE/NEET Online Test for Modern Physics( Multiple Choice Questions)


(A) Multiple choice questions with one answer
1. The ionizing power of the radiations are in the increasing order of
(a) &#947,&#946 ,&#945
(b) &#945 , &#946,&#947
(c) &#945 , &#947,&#946
(d) &#946, &#947,&#945

2.A photon of energy 5.0 eV imparts all it's energy to an electron that leaves a metal surface with 1.5 eV of kinetic energy.The work function &#945 of metal would be
(a) 6.5 eV
(b) 3.5 eV
(c) 3.9 eV
(d) 1.5 eV

3. A thermal neutron of mass 1.67&#215 10-27 Kg is travelling at a speed of 2500 m/s. de Brogli wavelength of thermal neutron is
(a) 1.4 &#215 10-10m
(b) 12 &#215 10-10m
(c) 1.6 &#215 10-10m
(d) 1.0 &#215 10-10m

4. Uncertainty in the position of a particle is equal to twice its de Brogli wavelength. Uncertainty in its velocity would be
(a) &#916vx&#8805(1/4&#960)vx
(b) &#916vx&#8805(1/&#960)vx
(c) &#916vx&#8805(1/2&#960)vx
(d) &#916vx&#8805(1/8&#960)vx

5. The shortest wavelength of X-Rays emitted from an X-Ray tube depends upon
(a) atomic number of target material
(b) current in the tube
(c) voltage applied to the tube
(d) nature of gas in the tube

6. The largest wavelength present in the Balmer series of hydrogen atom is
(a) 656 nm
(b) 500 nm
(c) 600 nm
(d) 756 nm

(B) Matrix match type
Match the list P with the list Q to name the series for quantum jump of electrons in hydrogen atom

list P
(a) n=2 to n=3
(b) n=3 to n=4
(c) n=4 to n=5
(d) n=5 to n=6

list Q
1. Balmer
2. lyman
3. Paschen
4. Brackett
5. Pfund

(A) Multiple choice questions with one answer
1. a
2. b
3. c
4. d
5. c
6. d

(B) Matrix match type


(A) Multiple choice questions

1. Photoelectric emission takes place when
(a)electrons falls on photosensitive surface
(b)alpha particles falls on photosensitive surface
(c)light rays falls on photosensitive surface
(d)neutrons falls on photosensitive surface

2. The velocity of most energetic photo electrons emitted from metal surface depends on
(a) time for which radiation fall on metal surface
(b) the frequency of incident light
(c) the intensity of incident light
(d) none of the above

3. The work function of a metal is w and &#955 is the wavelength of incident radiation. there would be no emission of photo electrons when
(a) &#955 > hc/w
(b) &#955 < hc/w
(c) &#955 = hc/w
(d) &#955 &#8804 hc/w

4. The fact that was not inferred from the Rutherford model of the atom was that the
(a) nucleus occupied a small space inside the atom
(b) nucleus consisted of neutrons and protons
(c) electrons were outside the nucleus of the atom
(d) nucleus was dense in nature

5. A graph showing the energy of the photo-electron as a function of the frequency of the radiation for a given emitting surface is best represented as




(B) Matrix match type question
6. Match the items mentioned with those given in group (P) with those given in group (Q)

(a) The concept of nuclear atom was
established from the experiment on the
(b) Wave aspect of matter was confirmed by
(c) Bohr theory was successful in explaining
(d) Photons may cause

(1) emission of electrons from the metal surface
(2) scattering of alpha particles by a gold foil
(3) diffraction of electrons by a crystal
(4) bright line spectra of hydrogen atom
(5) scattering of X-rays by electrons

1. (c)
2. (b)
3. (a)
4. (c)
5. (a)
6. a-2

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