JEE Main 2025 (Online) 8th April Evening Shift

MCQ (Single Correct Answer)

-1

For a nucleus of mass number A and radius R, the mass density of nucleus can be represented as

$A^{\frac{2}{3}}$

Independent of A

$A^3$

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

JEE Main 2025 (Online) 7th April Evening Shift

MCQ (Single Correct Answer)

-1

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

Assertion (A): The density of the copper $(^ {64}_{29} \text{Cu})$ nucleus is greater than that of the carbon $(^ {12}_{6} \text{C})$ nucleus.

Reason (R): The nucleus of mass number A has a radius proportional to $ A^{1/3} $.

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

(A) is correct but (R) is not correct

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

(A) is not correct but (R) is correct

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

JEE Main 2025 (Online) 3rd April Morning Shift

MCQ (Single Correct Answer)

-1

$$ \text { Match the LIST-I with LIST-II } $$

List - I		List - II
A.	$$ { }_0^1 \mathrm{n}+{ }_{92}^{235} \mathrm{U} \rightarrow{ }_{54}^{140} \mathrm{Xe}+{ }_{38}^{94} \mathrm{Sr}+2{ }_0^1 \mathrm{n} $$	I.	$$ \text { Chemical reaction } $$
B.	$$ 2 \mathrm{H}_2+\mathrm{O}_2 \rightarrow 2 \mathrm{H}_2 \mathrm{O} $$	II.	$$ \text { Fusion with +ve } \mathrm{Q} \text { value } $$
C.	$$ { }_1^2 \mathrm{H}+{ }_1^2 \mathrm{H} \rightarrow{ }_2^3 \mathrm{He}+{ }_0^1 \mathrm{n} $$	III.	$$ \text { Fission } $$
D.	$$ { }_1^1 \mathrm{H}+{ }_1^3 \mathrm{H} \rightarrow{ }_1^2 \mathrm{H}+{ }_1^2 \mathrm{H} $$	IV.	$$ \text { Fusion with -ve } Q \text { value } $$

$$ \text { Choose the correct answer from the options given below: } $$

A-II, B-I, C-III, D-IV

A-III, B-I, C-II, D-IV

A-III, B-I, C-IV, D-II

A-II, B-I, C-IV, D-III

JEE Main 2025 (Online) 2nd April Evening Shift

MCQ (Single Correct Answer)

-1

Energy released when two deuterons $\left({ }_1 \mathrm{H}^2\right)$ fuse to form a helium nucleus $\left({ }_2 \mathrm{He}^4\right)$ is : (Given : Binding energy per nucleon of ${ }_1 \mathrm{H}^2=1.1 \mathrm{MeV}$ and binding energy per nucleon of ${ }_2 \mathrm{He}^4=7.0 \mathrm{MeV}$ )

26.8 MeV

8.1 MeV

23.6 MeV

5.9 MeV

JEE Main Subjects