Four wires of equal length are bent in the form of four loops $P, Q, R$ and $S.$ These are suspended in a uniform magnetic field and the same current is passed through them. The maximum torque will act on:

$A$ current-carrying coil is subjected to a uniform magnetic field. The coil will orient itself so that its plane becomes

$A$ uniform magnetic field of $3000 \; G$ is established along the positive $z-$direction. $A$ rectangular loop of sides $10 \; cm$ and $5 \; cm$ carries a current of $12 \; A$. What is the torque on the loop in the different cases shown in Figure? What is the force on each case? Which case corresponds to stable equilibrium?

$A$ current-carrying coil experiences a torque due to a magnetic field. The value of the torque is $80 \%$ of the maximum possible torque. The angle between the magnetic field and the normal to the plane of the coil is

$A$ circular coil of $30$ turns and radius $8.0\, cm$ carrying a current of $6.0\, A$ is suspended vertically in a uniform horizontal magnetic field of magnitude $1.0\, T$. The field lines make an angle of $60^o$ with the normal of the coil. Calculate the magnitude of the counter torque that must be applied to prevent the coil from turning. (in $, Nm$)

$A$ small coil $C$ with $N = 200$ turns is mounted on one end of a balance beam and introduced between the poles of an electromagnet as shown in the figure. The cross-sectional area of the coil is $A = 1.0 \, cm^2$,and the length of the arm $OA$ of the balance beam is $l = 30 \, cm$. When there is no current in the coil,the balance is in equilibrium. On passing a current $I = 22 \, mA$ through the coil,the equilibrium is restored by putting an additional counterweight of mass $\Delta m = 60 \, mg$ on the balance pan. Find the magnetic induction $B$ at the spot where the coil is located. (in $, T$)