1
JEE Main 2023 (Online) 30th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

A small object at rest, absorbs a light pulse of power $$20 \mathrm{~mW}$$ and duration $$300 \mathrm{~ns}$$. Assuming speed of light as $$3 \times 10^{8} \mathrm{~m} / \mathrm{s}$$, the momentum of the object becomes equal to :

A
$$1 \times 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$
B
$$0.5 \times 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$
C
$$3 \times 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$
D
$$2 \times 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$
2
JEE Main 2023 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The ratio of de-Broglie wavelength of an $$\alpha$$ particle and a proton accelerated from rest by the same potential is $$\frac{1}{\sqrt m}$$, the value of m is -

A
2
B
16
C
8
D
4
3
JEE Main 2023 (Online) 29th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The threshold wavelength for photoelectric emission from a material is 5500 $$\mathop A\limits^o $$. Photoelectrons will be emitted, when this material is illuminated with monochromatic radiation from a

A. 75 W infra-red lamp

B. 10 W infra-red lamp

C. 75 W ultra-violet lamp

D. 10 W ultra-violet lamp

Choose the correct answer from the options given below :

A
C only
B
A and D only
C
C and D only
D
B and C only
4
JEE Main 2023 (Online) 25th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Given below are two statements :

Statement I : Stopping potential in photoelectric effect does not depend on the power of the light source.

Statement II : For a given metal, the maximum kinetic energy of the photoelectron depends on the wavelength of the incident light.

In the light of above statements, choose the most appropriate answer from the options given below

A
Both Statement I and Statement II are incorrect
B
Statement I is correct but Statement II is incorrect
C
Both Statement I and Statement II are correct
D
Statement I is incorrect but Statement II is correct
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