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: n=800, A=2.5×10−4m2, I=3.0A A magnetic field develops along the axis of the solenoid. Therefore current-carrying solenoid acts like a bar magnet. m=nIA=800×3×2.5×10−4JT−1 =0.6JT−1 along the axis of the solenoid.