A circular loop carrying a current a current I has wire of total length L. A uniform magnetic field B exists parallel to the plane of the loop. (a ) find the torque on the loop.(b) If the same length of the wire is used to form a square loop, what would be the torque? Which is larger?

Explanation

(a) `Radiud = r_(1)`
`Circnderence = L = 2 pi r_(1)`
So, `a = (L^(2))/(4pi)`
`tau = nia B = (iL^(2) B )/(4 pi)`
`(b) 4s = L rArr s == (L)/(4)`
`area = ((L)/(4))^(2) = ((L^(2))/(16))`
`tau = nia B = (iL^(2)B)/(16)`