Question

If the anti-neutrino had a mass of $3eV/c^2$ (where c is the speed of light) instead of zero mass, what should be the range of the kinetic energy, K of the electron?

• A. $0\le K\le 0.8\times {10}^{6}eV$
• B. $3.0eV\le K\le 0.8\times {10}^{6}eV$
• C. $3.0eV\le K<0.8\times {10}^{6}eV$
• D. $0\le K<0.8\times {10}^{6}eV$

Answer 1

The correct option is D $0\le K<0.8\times {10}^{6}eV$

As the anti neutrino is not mass less, a small quantity of energy is carried by it.
Hence electron cannot have its maximum K.E
It will be slightly less than that.
Hence, $0\le K<0.8\times {10}^{6}eV$