A long solenoid of 50   cm length having 100 turns carries a current of 2.5   A . The magnetic field at the centre of the solenoid is: μ 0 = 4 π × 10 − 7 T   m   A − 1

Step-by-step solution

The magnetic field at the centre of the solenoid is given by, B = μ 0 n i Where n is the number of turns per unit length ⇒ B = 4 π × 10 - 7 × 100 ( 0 . 5 ) × 2 . 5 ⇒ B = 6 . 28 × 10 - 4   T