Year: 2020
Topic: Moving charges and magnetism
Time :
1. 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
= 4π × 10
−7
T mA
−1
)
(1). 3.14 × 10
−4
T
(2). 6.28 × 10
−5
T
(3). 3.14 × 10
−5
T
(4). 6.28 × 10
−4
T