Magnetic field induction at point insides the solenoid of length l, having n turns per unit length carrying current i. is given by B=μ0ni If i is double and n is halved then B remains same.
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:
Held on 30 Apr 2003 · Verified 9 Jul 2026.
2B
B
2B
4B
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