A closely wound solenoid of 800 turns and area of cross section 2.5 × 10–4 m2 carries a current of 3.0 A. Explain the sense in which the solenoid acts like a bar magnet. What is its associated magnetic moment?

Given:


Number of turns, N = 800


Area of cross-section, A = 2.5 × 10-4 m2


Current, I = 3A


The solenoid acts like a bar magnet because the magnetic axis of the solenoid is along its length, which is analogous to the magnetic axis of Bar magnet.


We know that,


Magnetic moment, M = N × I × A …(1)


Now putting the values in equation 1, we get


M = 800 × 3A × 2.5 × 10-4m2


M = 0.6 JT-1


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