AIIMS 2017
- Exam
- AIIMS
- Year
- 2017
- Subject
- Physics
- Chapter
- Electrostatics
AIIMS 2017 · Physics · Electrostatics
A large solid sphere with uniformly distributed positive charge has...
A large solid sphere with uniformly distributed positive charge has a smooth narrow tunnel through its centre. A small particle with negative charge, initially at rest far from the sphere, approaches it along the line of the tunnel, reaches its surface with a speed , and passes through the tunnel. Its speed at the centre of the sphere will be
Options
- A
- BV
- C
- D
Correct answer
D.
Step-by-step solution
Potential at infinity
Potential at the surface of the sphere,
Potential at the centre of the sphere,
Let be the mass and the charge of the particle respectively.
Let speed of the particle at the centre of the sphere.
Dividing eqn. (ii) by eqn. (i),
or