AP EAMCET202018 Sep 2020Evening ShiftPhysicsMagnetic Effects of CurrentActual
A straight wire carrying current (i ) is turned into a circular loop. If the magnitude of magnetic moment associated with it in MKS units is (M ), the length of wire will be
Options
- A(4 i M )
- B( 4 M i )
- C( 4 i M )
- D( M 4 i )
Correct answer
B. ( 4 M i )
Step-by-step solution
Suppose, (l ) be the length of wire. Hence, ( l=2 r r= l 2 ) ( ) Magnetic dipole moment, ( aligned M & =i A M & =i r^2 =i ( l 2 )^2=i l^2 4 ^2 M & = i l^2 4 l^2 & = 4 M i l= 4 M i aligned )