Q.

A square loop of side 2a and carrying current I is kept in xz plane with its centre at origin.  A long wire carrying the same current I is placed parallel to z-axis and passing through point  (0,b,0),  b>>a.  The magnitude of torque on the loop about z-axis will be :

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

a

2μ0I2a2bπa2+b2

b

2μ0I2a2πb

c

μ0I2a22πb

d

μ0I2a2b2πa2+b2

answer is C.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

detailed_solution_thumbnail

Magnetic moment of loop is  4a2Ij^ and magnetic filed induction at origin due to long wire B=μoI2πbi^ . 

So as b>>a,  τ=M×B=2μoI2a2πb

Watch 3-min video & get full concept clarity
score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon
A square loop of side 2a and carrying current I is kept in xz plane with its centre at origin.  A long wire carrying the same current I is placed parallel to z-axis and passing through point  (0,b,0) ,  b>>a.  The magnitude of torque on the loop about z-axis will be :