JEE Main20257 Apr 2025Evening ShiftPhysicsNuclear PhysicsActual
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 ( ₂₉⁶⁴ Cu ) nucleus is greater than that of the carbon ( ₆¹² 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 :
Options
- A( A ) is correct but ( R ) is not correct
- B( A ) is not correct but ( R ) is correct
- CBoth ( A ) and ( R ) are correct and ( R ) is the correct explanation of (A)
- DBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
Correct answer
B. ( A ) is not correct but ( R ) is correct
Step-by-step solution
= M ~V = m _ n A 4 3 R ^3 = m _ n A 4 3 AR ₀^3 So is almost is constant aligned & R = R ₀ ~A ^ 1 / 3 & R ~A ^ 1 / 3 aligned