Question

Four wires, each of length 2.0 m, are bent into four loops P, Q, R and S and then suspended in a uniform magnetic field. If the same current is passed in each, then the torque will be maximum on the loop(a) P(b) Q(c) R(d) S

Answer 1

d will have the maximum torque

Answer 2

Answer:

D) S

Explanation:

Length of four wires = 2m (Given)

Bent into loops = 4 - P Q R and S  (Given)

For the given parameter a circle has the largest area. Thus,

T = M→×B→

T = InAB

so TαA

Thus area is greater which leads to more torque. The couple of force on loop S will be maximum. This is because, for same perimeter the area of loop will be maximum and magnetic moment of loop is =i×A. So, it will also be maximum for loop S. Thus, If the same current is passed in each, then the torque will be maximum on the loop S