A closely wound solenoid of 800 turns and area of cross-section 2.5 ×

1.	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?
Answer» Given N = 800, A = 2.5 × 10^-4 m² , I = 3.0 A, M = ? Since M = NIA ∴ M = 800 × 3 × 2.5 × 10^-4 or M = 0.60 JT^-1 along the axis of the solenoid.

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?

Answer»

Given N = 800, A = 2.5 × 10^-4 m² , I = 3.0 A, M = ?

Since M = NIA

∴ M = 800 × 3 × 2.5 × 10^-4

or M = 0.60 JT^-1 along the axis of the solenoid.