Question

An electron moves in circular orbit of radius r cm with a speed v m/s in presence of magnetic field B. The energy gained by the electron in going once round the circular orbit is

• A. $\frac { \mathrm { mv } ^ { 2 } } { \mathrm { r } }$
• B. 2prmv
• C. Zero
• D. None of these

Answer 1

Answer: (C)

Zero

Answer 2

When charge moves on circular path in effect of normal magnetic field then KE = constant.