AP EAMCET202023 Sep 2020Morning ShiftPhysicsMagnetic Effects of CurrentActual
An electron having charge 1 . 6 × 10 - 19 C and mass 9 × 10 - 31 kg is moving with 4 × 10 6 m s - 1 speed in a magnetic field 2 × 10 - 1 T in a circular orbit. The force acting on electron and the radius of the circular orbit is _____
Options
- A12 . 8 × 10 - 13   N , 1 . 1 × 10 - 4   m
- B1 . 28 × 10 - 14   N , 1 . 1 × 10 - 3   m
- C1 . 28 × 10 - 13   N , 1 . 1 × 10 - 3   m
- D1 . 28 × 10 - 13   N , 1 . 1 × 10 - 4   m
Correct answer
D. 1 . 28 × 10 - 13   N , 1 . 1 × 10 - 4   m
Step-by-step solution
Force due to magnetic field on moving charge is given by F = q v B ⇒ F = 1 . 6 × 10 - 19 × 4 × 10 6 × 2 × 10 - 1 = 1 . 28 × 10 - 3   N Radius of circular path F = m v 2 r ⇒ r = m v 2 F = 9 × 10 - 31 × 4 × 10 6 2 1 . 28 × 10 - 13 = 1 . 1 × 10 - 4   m