A long solenoid carrying a current produces a magnetic field B along its axis . If the current is doubled and the number of turns per cm is halved, the new value of the magnetic field is (a) B/2 (b) B (c) 2B (d) 4B
Magnetic field induction at point inside the solenoid of length l, having n turns per unit length carrying current i is given by B=uoni If i is doubled, and n is having then B remains same.
