NEET2022PhysicsMagnetic Effects of CurrentActual
A long solenoid of radius 1   mm has 100   turns per mm . If 1   A current flows in the solenoid, the magnetic field strength at the centre of the solenoid is:
Options
- A12 . 56 × 10 - 2   T
- B12 . 56 × 10 - 4   T
- C6 . 28 × 10 - 4   T
- D6 . 28 × 10 - 2   T
Correct answer
A. 12 . 56 × 10 - 2   T
Step-by-step solution
Radius = 1   mm N = 100   turns per mm Current = 1   A Magnetic field strength at the centre of the solenoid is, B = μ 0 n i = 4 π × 10 - 7 × 100 × 10 3 × 1 ⇒ B = 12 . 56 × 10 - 2   T