Question

An electron moves in a circular arc of radius $10\, m$ at a constant speed of $2 \times 10^{7} \,ms ^{-1}$ with its plane of motion normal to a magnetic flux density of $10^{-5}\, T$. What will be the value of specific charge of the electron?

• A. $2 \times 10^{4} \,Ckg ^{-1}$
• B. $2 \times 10^{5} \,Ckg ^{-1}$
• C. $5 \times 10^{6} \,Ckg ^{-1}$
• D. $2 \times 10^{11} \,Ckg ^{-1}$

Answer 1

Answer: (D)

$B q v=\frac{m v^{2}}{r}$ or $\frac{q}{m}=\frac{v}{r B}$