Question

The total kinetic energy, of the electron antineutrinos pair, in the β –decay process, equals 8.10 ×10⁶ eV. The antineutrinos, formed in this decay, could escape with a maximum kinetic energy of

(1) zero

(2) Much less than 8.0×10⁶ eV 

(3) Nearly 0.8×10⁶ eV 

(4) Much larger than 0.8×106 eV

Answer 1

Correct option : (2) Much less than 8.0×10⁶ eV

Explanation: 

The following reaction represents β decay process

In this decay process the kinetic energy of the pair of electron and antineutrons is constant. When K.E of electron is maximum, K.E. of bar v is zero.  The antineutrinos will have maximum energy when K.E of electron is zero. Maximum K.E of antineutron will be nearly 0.8×10⁶ eV.