$A$ loop is formed by a wire of constant length carrying a current $I$ and placed in an external magnetic field $\vec{B}$. The torque $\vec{\tau}$ acting on it depends on which of the following factors?

$A$ coil carrying electric current is placed in a uniform magnetic field,then

$A$ rectangular loop of sides $10 \ cm$ and $5 \ cm$ carrying a current $I$ of $12 \ A$ is placed in different orientations as shown in the figures below. If there is a uniform magnetic field of $0.3 \ T$ in the positive $z$ direction,in which orientations would the loop be in $(i)$ stable equilibrium and $(ii)$ unstable equilibrium?

$A$ uniform magnetic field of $2 \times 10^{-3} \ T$ acts along the positive $Y$-direction. $A$ rectangular loop of sides $20 \ cm$ and $10 \ cm$ carrying a current of $5 \ A$ is placed in the $Y-Z$ plane. The current flows in an anticlockwise sense with reference to the negative $X$-axis. Find the magnitude and direction of the torque.

$(a)$ $A$ current-carrying circular loop lies on a smooth horizontal plane. Can a uniform magnetic field be set up in such a manner that the loop turns around itself (i.e.,turns about the vertical axis)?
$(b)$ $A$ current-carrying circular loop is located in a uniform external magnetic field. If the loop is free to turn,what is its orientation of stable equilibrium? Show that in this orientation,the flux of the total field (external field $+$ field produced by the loop) is maximum.
$(c)$ $A$ loop of irregular shape carrying current is located in an external magnetic field. If the wire is flexible,why does it change to a circular shape?

$A$ circular coil of $20$ turns and radius $10\; cm$ is placed in a uniform magnetic field of $0.10\; T$ normal to the plane of the coil. If the current in the coil is $5.0\; A$,what is the
$(a)$ total torque on the coil,
$(b)$ total force on the coil,
$(c)$ average force on each electron in the coil due to the magnetic field?
(The coil is made of copper wire of cross-sectional area $10^{-5} \;m ^{2},$ and the free electron density in copper is given to be about $10^{29}\; m ^{-3}.$)