$A$ power line lies along the east-west direction and carries a current of $10\, A$. The force per metre due to the earth's magnetic field of ${10^{ - 4}}\, T$ is

Three long straight wires are carrying current as shown in the diagram. The magnetic force per unit length on wire $Q$ is $..... \times 10^{-7} \ N/m$.

If a current is passed through a spring,then the spring will:

The force acting per unit length on a very long straight conductor carrying a steady current of $1 \,A$ flowing from south to north is: (The horizontal component of the earth's magnetic field at the place is $3 \times 10^{-5} \,T$ and its direction is from geographical south to geographical north.)

$A$ current $i = 2 \, A$ flows through a wire frame as shown in the figure. The frame is a combination of two equilateral triangles $ACD$ and $CDE$ with side length $1 \, m$. It is placed in a uniform magnetic field $B = 4 \, T$ acting perpendicular to the plane of the frame. The magnitude of the net magnetic force acting on the frame is.......$N$.

$A$ square loop of length $L$ is placed with its edges parallel to the $XY$-axes. The loop carries a current $I$. If the magnetic field in the region varies as $B = B_0 \left(1 + \frac{xy}{L^2}\right) \hat{k}$,then the magnitude of the net force on the loop will be: