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

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

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

The frequency of revolution of the electron in Bohr's orbit varies with n, the principal quantum number as:

A

$ \frac{1}{n^4} $

B

$ \frac{1}{n^2} $

C

$ \frac{1}{n^3} $

D

$ \frac{1}{n} $

3
JEE Main 2025 (Online) 28th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Choose the correct nuclear process from the below options [ p : proton, n : neutron, $\mathrm{e}^{-}$: electron, $\mathrm{e}^{+}$: positron, $v:$ neutrino, $\bar{v}:$ antineutrino]

A
$n \rightarrow p+e^{+}+{v}$
B
$\mathrm{n} \rightarrow \mathrm{p}+\mathrm{e}^{-}+\bar{v}$
C
$\mathrm{n} \rightarrow \mathrm{p}+\mathrm{e}^{+}+\bar{v}$
D
$\mathrm{n} \rightarrow \mathrm{p}+\mathrm{e}^{-}+v$
4
JEE Main 2025 (Online) 24th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The energy E and momentum p of a moving body of mass m are related by some equation. Given that c represents the speed of light, identify the correct equation

A
$\mathrm{E}^2=\mathrm{pc}^2+\mathrm{m}^2 \mathrm{c}^4$
B
$\mathrm{E}^2=\mathrm{pc}^2+\mathrm{m}^2 \mathrm{c}^2$
C
$\mathrm{E}^2=\mathrm{p}^2 \mathrm{c}^2+\mathrm{m}^2 \mathrm{c}^4$
D
$\mathrm{E}^2=\mathrm{p}^2 \mathrm{c}^2+\mathrm{m}^2 \mathrm{c}^2$
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