Question

A solenoid of length 25 cm has an inner radius of 1 cm and is made up of 250 turns of copper wire. For a current of 3 A in it, what will be the magnitude of the magnetic field inside the solenoid?
(a) 5.03 mT
(b) 6.28 mT
(c) 7.45 mT
(d) 9.12 mT