In a solenoid, the current flowing through the wire is I and number of turns per unit length is n . This gives a magnetic field B inside the solenoid. If number of turn per unit length is increased to 2 n , what will be the value of magnetic field in the solenoid?

Step-by-step solution

A long solenoid is the one which has a larger length in comparison to the radius. It consists of a long wire wound in the form of a helix where the neighboring turns are closely spaced. So each turn can be regarded as a circular loop. The net magnetic field is the vector sum of the fields due to all the turns. Enamelled wires are used for winding so that turns are insulated from each other. The magnetic field inside a long solenoid is: B = ₀ nI . (1) where n = number of turns per unit length and I = current flowing