JEE Main · 2022 · 28 Jun 2022 · Shift 1 · Modern Physics

The Q-value of a nuclear reaction and kinetic energy of the projectile particle,

K_{p}

are related as:

(A) $Q = K_{p}$
(B) $(K_{p} + Q) < 0$
(C) $Q < K_{p}$
(D) $(K_{p} + Q) > 0$ ✓ Correct

Answer: (D)

Solution

In a nuclear reaction

x + p \to γ + b

, the Q-value is defined as

Q = K_{γ} + K_{b} - K_{p}

, where

K_{p}

is the kinetic energy of the projectile and

K_{γ}, K_{b}

are the kinetic energies of the products. Rearranging:

Q + K_{p} = K_{γ} + K_{b}

. Since kinetic energies are positive,

Q + K_{p} > 0

. The answer is (D).

JEE Main · 2022 · 28 Jun 2022 · Shift 1 · Single correct option

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