A small circular flexible loop of wire of radius. r carries a current I. It is placed in a uniform magnetic field B. The tension in the loop will be doubled if

Question

A small circular flexible loop of wire of radius. r carries a current I. It is placed in a uniform magnetic field B. The tension in the loop will be doubled if (A) I is halved (B) B is halved (C) r is doubled (D) both B and I are doubled

Tardigrade Admin · Accepted Answer

When a circular flexible loop is placed in a magnetic field, a deflecting torque

(τ)

acts on it, this is given by

τ = MB sin θ

Also,

= I A

∴ τ = I A B sin θ = I π r^{2} B sin θ

When

B

and

I

are doubled, the torque is doubled, hence tension is doubled.

Q. A small circular flexible loop of wire of radius. r carries a current I. It is placed in a uniform magnetic field B. The tension in the loop will be doubled if

I is halved

B is halved

r is doubled

both B and I are doubled

When a circular flexible loop is placed in a magnetic field, a deflecting torque (τ) acts on it, this is given by τ=MBsinθ Also, =IA ∴τ=IABsinθ=Iπr2Bsinθ When B and I are doubled, the torque is doubled, hence tension is doubled.

Q. A small circular flexible loop of wire of radius. $r$ carries a current $I .$ It is placed in a uniform magnetic field $B$ . The tension in the loop will be doubled if

When a circular flexible loop is placed in a magnetic field, a deflecting torque $(τ)$ acts on it, this is given by
$τ = MB sin θ$
Also, $= I A$
$∴ τ = I A B sin θ = I π r^{2} B sin θ$
When $B$ and $I$ are doubled, the torque is doubled, hence tension is doubled.