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

Explanation

a) Torque `=300, G = 3000 xx10^(-4) T`
Area `A=10 xx5=50cm^(2)=(50)/(100xx100)m^(2)`
`tau= BIA =(3)/(10)xx12xx(50)/(100xx100)=18xx10^(-2)` Nm along Y-axis
b) Same as in (a)
c) `1.8xx10^(-2)` Nm along x-direction
d) `1.8xx10^(-2)` Nm at an anlge `340^(@)` with the +x direction
e) Zero
f) Zero
Force is zero in each case. Case (e ) corresponds to stable and case (f) to unstable equilibrium.