JEE Main202330 Jan 2023Evening ShiftPhysicsNuclear PhysicsActual
Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R Assertion A : The nuclear density of nuclides B 5 10 , L 3 6 i , F 26 56 e , N 10 20 e and B 83 209 i can be arranged as ρ B i N > ρ F e N > ρ N e N > ρ B N > ρ L i N Reason R : The radius R of nucleus is related to its mass number A as R = R 0 A 1 3 , where R 0 is a constant.
Options
- ABoth A and R are true and R is the correct explanation of A
- BA is false but R is true
- CA is true but R is false
- DBoth A and R are true but R is NOT the correct explanation of A
Correct answer
B. A is false but R is true
Step-by-step solution
Nuclear density is given by, ρ = m 4 3 π R 0 3 , where m is mass of proton. Clearly it is independent of A and same for all nucleus. Radius of the nucleus is given by, R = R 0   A 1 3 .