1
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
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In an experiment with photoelectric effect, the stopping potential,

A

is $\left(\frac{1}{e}\right)$ times the maximum kinetic energy of the emitted photoelectrons

B

increases with increase in the intensity of the incident light

C

decreases with increase in the intensity of the incident light

D

increases with increase in the wavelength of the incident light

2
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
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The number of spectral lines emitted by atomic hydrogen that is in the 4th energy level, is

A

3

B

6

C

1

D

0

3
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The difference of temperature in a material can convert heat energy into electrical energy. To harvest the heat energy, the material should have

A

low thermal conductivity and high electrical conductivity

B

low thermal conductivity and low electrical conductivity

C

high thermal conductivity and high electrical conductivity

D

high thermal conductivity and low electrical conductivity

4
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : With the increase in the pressure of an ideal gas, the volume falls off more rapidly in an isothermal process in comparison to the adiabatic process.

Reason (R) : In isothermal process, PV = constant, while in adiabatic process $PV^{\gamma}$ = constant. Here $\gamma$ is the ratio of specific heats, P is the pressure and V is the volume of the ideal gas.

In the light of the above statements, choose the correct answer from the options given below:

A

(A) is true but (R) is false

B

Both (A) and (R) are true but (R) is NOT the correct explanation of (A)

C

(A) is false but (R) is true

D

Both (A) and (R) are true and (R) is the correct explanation of (A)

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