1
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
2
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
3
JEE Main 2023 (Online) 25th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Electron beam used in an electron microscope, when accelerated by a voltage of 20 kV, has a de-Broglie wavelength of $$\lambda_0$$. IF the voltage is increased to 40 kV, then the de-Broglie wavelength associated with the electron beam would be :

A
3 $$\lambda_0$$
B
9 $$\lambda_0$$
C
$$\frac{\lambda_0}{\sqrt2}$$
D
$$\frac{\lambda_0}{2}$$
4
JEE Main 2023 (Online) 24th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
An $$\alpha$$-particle, a proton and an electron have the same kinetic energy. Which one of the following is correct in case of their de-Broglie wavelength:
A
$${\lambda _\alpha } > {\lambda _p} < {\lambda _e}$$
B
$${\lambda _\alpha } > {\lambda _p} > {\lambda _e}$$
C
$${\lambda _\alpha } = {\lambda _p} = {\lambda _e}$$
D
$${\lambda _\alpha } < {\lambda _p} < {\lambda _e}$$
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