The minimum frequency of a `gamma`-ray that causes a deutron to disintegrate into a poton and a neutron is `(m_(d)=2.0141 am u, m_p=1.0078 am u, m_n=1.0087 am u.)`.

Options

A. `2.7 xx 10^(20)Hz`
B. `5.4 xx10^(20)Hz`
C. `10.8 xx10^(20)Hz`
D. `21.6xx10^(20)Hz`

Answer

b

Explanation

Total mass of the products `=2.0165 a.m.u.`, which is greater than the mass of the deutron by `0.0024 a.m.u.` The extra mass must be provided by the energy of the photon so that minimum possible frequency must be given by
`v=(0.0024 a.m.u. c^(2))/(h)" "(1 a.m.u. =1.66 xx 10^(-27) kg)`
` =5.4 xx 10^(20) Hz`.