KCET2014PhysicsAlternating Current
A circular coil of radius ( 10 ~cm ) and ( 100 ) turns carries a current ( 1 ~A ). What is the magnetic moment of the coil ?
Options
- A( 3.142 10⁴ ~A ~m ² )
- B( 10⁴ Am ² )
- C( 3.142 Am ² )
- D( 3 A ~m ² )
Correct answer
C. ( 3.142 Am ² )
Step-by-step solution
Given, radius of coil, r=10 ~cm =10 10⁻² ~m ; number of turns, N =100 ; current, I =1 ~A . We know, magnetic moment of coil, M = NIA Where A = area = r² Therefore, M=N inr ²=100 1 3.14 (10 10⁻² )²=3.142 Am ² Magnetic moment of the coil is 3.142 Am ²