1
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

A photon emitted during the de-excitation of electron from a state $$\mathrm{n}$$ to the second excited state in a hydrogen atom, irradiates a metallic electrode of work function $$0.5 \mathrm{~eV}$$, in a photocell, with a stopping voltage of $$0.47 \mathrm{~V}$$. Obtain the value of quantum number of the state '$$n$$'.

A
5
B
6
C
4
D
3
2
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

A particle of mass $$2 \mathrm{mg}$$ has the same wavelength as a neutron moving with a velocity of $$3 \times 10^5 \mathrm{~ms}^{-1}$$. The velocity of the particle is (mass of neutron is $$1.67 \times 10^{-27} \mathrm{Kg}$$)

A
$$2.5 \times 10^{-16} \mathrm{~ms}^{-1}$$
B
$$1.5 \times 10^{-13} \mathrm{~ms}^{-1}$$
C
$$2.5 \times 10^{-13} \mathrm{~ms}^{-1}$$
D
$$1.5 \times 10^{-16} \mathrm{~ms}^{-1}$$
3
COMEDK 2024 Morning Shift
MCQ (Single Correct Answer)
+1
-0

The threshold frequency for a metal surface is '$$n_0$$'. A photo electric current '$$I$$' is produced when it is exposed to a light of frequency $$\left(\frac{11}{6}\right) \mathrm{n}_{\mathrm{o}}$$ and intensity $$\mathrm{I}_{\mathrm{n}}$$. If both the frequency and intensity are halved, the new photoelectric current '$$\mathrm{I}^1$$' will become:

A
$$\mathrm{I}^1=\frac{1}{4} \mathrm{I}$$
B
$$\mathrm{I}^1=2 \mathrm{I}$$
C
$$\mathrm{I^1=0}$$
D
$$\mathrm{I}^1=\frac{1}{2} \mathrm{I}$$
4
COMEDK 2024 Morning Shift
MCQ (Single Correct Answer)
+1
-0

The mass of a particle $$\mathrm{A}$$ is double that of the particle $$\mathrm{B}$$ and the kinetic energy of $$\mathrm{B}$$ is $$\frac{1}{8}$$th that of A then the ratio of the de- Broglie wavelength of A to that of B is:

A
1 : 2
B
2 : 1
C
1 : 4
D
4 : 1
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