1
JEE Main 2025 (Online) 28th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Which of the following phenomena cannot be explained by wave theory of light?

A

Refraction of light

B

Reflection of light

C

Diffraction of light

D

Compton effect

2
JEE Main 2025 (Online) 28th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

A proton of mass ' $m_P$ ' has same energy as that of a photon of wavelength ' $\lambda$ '. If the proton is moving at non-relativistic speed, then ratio of its de Broglie wavelength to the wavelength of photon is.

A
$\frac{1}{c} \sqrt{\frac{E}{m_p}}$
B
$\frac{1}{\mathrm{c}} \sqrt{\frac{2 \mathrm{E}}{\mathrm{m}_{\mathrm{p}}}}$
C
$\frac{1}{\mathrm{2c}} \sqrt{\frac{ \mathrm{E}}{\mathrm{m}_{\mathrm{p}}}}$
D
$\frac{1}{\mathrm{c}} \sqrt{\frac{\mathrm{E}}{2 \mathrm{~m}_{\mathrm{p}}}}$
3
JEE Main 2025 (Online) 24th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

In photoelectric effect, the stopping potential $\left(\mathrm{V}_0\right) \mathrm{v} / \mathrm{s}$ frequency $(v)$ curve is plotted.

( h is the Planck's constant and $\phi_0$ is work function of metal )

(A) $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ is linear.

(B) The slope of $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ curve $=\frac{\phi_0}{\mathrm{~h}}$

(C) h constant is related to the slope of $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ line.

(D) The value of electric charge of electron is not required to determine h using the $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ curve.

(E) The work function can be estimated without knowing the value of $h$.

Choose the correct answer from the options given below :

A
(A), (C) and (E) only
B
(C) and (D) only
C
(A), (B) and (C) only
D
(D) and (E) only
4
JEE Main 2025 (Online) 24th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

An electron of mass ' m ' with an initial velocity $\overrightarrow{\mathrm{v}}=\mathrm{v}_0 \hat{i}\left(\mathrm{v}_0>0\right)$ enters an electric field $\overrightarrow{\mathrm{E}}=-\mathrm{E}_{\mathrm{o}} \hat{\mathrm{k}}$. If the initial de Broglie wavelength is $\lambda_0$, the value after time t would be

A
$\frac{\lambda_o}{\sqrt{1-\frac{\mathrm{e}^2 \mathrm{E}_{\mathrm{o}}^2 \mathrm{t}^2}{\mathrm{~m}^2 \mathrm{v}_{\mathrm{o}}^2}}}$
B
$\lambda_0$
C
$\frac{\lambda_o}{\sqrt{1+\frac{\mathrm{e}^2 \mathrm{E}_{\mathrm{o}}^2 \mathrm{t}^2}{\mathrm{~m}^2 v_o^2}}}$
D
$\lambda_{\mathrm{o}} \sqrt{1+\frac{\mathrm{e}^2 \mathrm{E}_{\mathrm{o}}^2 \mathrm{t}^2}{\mathrm{~m}^2 \mathrm{v}_{\mathrm{o}}^2}}$
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