The magnetic field existing in a region is given by $\vec B\, = {B_0}\,\left[ {1 + \frac{x}{l}} \right]\,\hat k\,A$ square loop of edge $l$  and carrying current $I_0$ , is placed with its edges parallel to the $x-y$ axis . Find the magnitude of the net magnetic force experienced by the loop 

A wire carrying a current $I$ along the positive $x$-axis has length $L$ It is kept in a magnetic field $\overrightarrow{ B }=(2 \hat{ i }+3 \hat{ j }-4 \hat{ k }) T$. The magnitude of the magnetic force acting on the wire is $..........IL$

Find force per unit length at $P$.

A one metre long wire is lying at right angles to the magnetic field. A force of $1\, kg$ wt. is acting on it in a magnetic field of $0.98\, Tesla$. The current flowing in it will be....$A$

A circular coil of wire carries a current. $PQ$ is a part of a very long wire carrying a current and passing close to the circular coil. If the directions of currents are those shown in figure, what is the direction of force acting on $PQ$ ?

Two long straight parallel conductors separated by a distance of $0.5\,m$ carry currents of $5\,A$ and $8\,A$ in the same direction. The force per unit length experienced by each other is