The Total solution for NCERT class 6-12
A closely wound solenoidof 2000 turns and area of cross-section 1.6 × 10−4 m2,carrying a current of 4.0 A, is suspended through its centre allowing it toturn in a horizontal plane.
(a) What is the magneticmoment associated with the solenoid?
Number of turnson the solenoid, n = 2000
Area of cross-section ofthe solenoid, A = 1.6 × 10−4 m2
Current in thesolenoid, I = 4 A
(a)The magnetic momentalong the axis of the solenoid is calculated as:
M = nAI
=2000 × 1.6 × 10−4 × 4
= 1.28 Am2
(b)Magnetic field, B =7.5 × 10−2 T
Angle between themagnetic field and the axis of the solenoid, θ = 30°