Question

The specific charge of a proton is $9.6 \times 10^7 \, C \, kg^{-1}$. The specific charge of an alpha particle will be :

• A. $9.6 \times 10^{7} \,C \, kg^{-1}$
• B. $19.2 \times10^{7}\, C \, kg^{-1}$
• C. $4.8 \times10^{7} \,C \,kg^{-1}$
• D. $2.4 \times10^{7}\, C \,kg^{-1}$

Answer 1

Answer: (C)

Specific charge on proton $=\left(\frac{e}{m}\right)_{p}$
$9.6 \times 10^{7} C / kg $ specific charge
$\left(\frac{q}{m}\right)_{\alpha}=\frac{2 e}{4 m} =\frac{1}{2}\left(\frac{e}{m}\right)_{p}=\frac{1}{2} \times 9.6 \times 10^{7}$
$=4.8 \times 10^{7} C / kg$