Question -
Answer -
Magnetic field strength, B =3000 G = 3000 × 10−4 T = 0.3 T
Length of the rectangular loop, l =10 cm
Width of the rectangularloop, b = 5 cm
Area of the loop,
A = l × b =10 × 5 = 50 cm2 = 50 × 10−4 m2
Current in the loop, I =12 A
Now, taking the anti-clockwisedirection of the current as positive and vise-versa:
(a) Torque, 
Fromthe given figure, it can be observed that A is normal tothe y-z plane and B is directed alongthe z-axis.The torque is 
N m along thenegative y-direction. The force on the loop is zero because theangle between A and B is zero.
(b) Thiscase is similar to case (a). Hence, the answer is the same as (a).
(c) Torque 
From the given figure, it can beobserved that A is normal to the x-z planeand B is directed along the z-axis.
The torque is N m along thenegative x direction and the force is zero.
(d) Magnitude of torqueis given as:
Torque is N m at an angle of 240°with positive x direction. The force is zero.
(e) Torque Hence, the torque is zero. Theforce is also zero.
(f) Torque Hence, the torque is zero. Theforce is also zero.
Incase (e), the direction of 
and 
is the same and the angle betweenthem is zero. If displaced, they come back to an equilibrium. Hence, itsequilibrium is stable.