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A long solenoid carrying a current produ...

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

B

2B

C

4B

D

`B/2`

Text Solution

Verified by Experts

The correct Answer is:
A
A long solenoid carrying a current produces magnetic field B along its axis.
Now if the current I is doubled and the number of turns n per cm is halved the magnetic field
`B.=mu_(0)n/2xx2I=Bmu_(0)nI=B`
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