If a wire of length $1\, m$ is placed in a uniform magnetic field of $1.5\, T$ at an angle of ${30^\circ}$ with the magnetic field,and the current in the wire is $10\, A$,then the force on the wire will be.......$N$. (in $.5$)

$A$ wire loop of irregular shape carrying current is placed in an external magnetic field. If the wire is flexible,the shape of the loop changes to

The resultant force on the current loop $PQRS$ due to a long current-carrying conductor is:

Give the uses of electromagnets.

Two wires $2 \text{ mm}$ apart supply current to a $100 \text{ V}$,$1 \text{ kW}$ heater. The force per metre between the wires is (Given $\mu_0 = 4\pi \times 10^{-7} \text{ T m/A}$)

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