Question

A long solenoid of radius 1 mm has 100 turns per mm. If 1A current flows in the solenoid, the magnetic field strength at the center of the solenoid is 

(1) 12.56 x 10^–2 T 

(2) 12.56 x 10^–4 T 

(3) 6.28 x 10^–4 T 

(4) 6.28 x 10^–2 T

Answer 1

(1) 12.56 x 10^–2 T