Two parallel conductors carrying unequal currents in the same direction . . . . . .

Three long,straight parallel wires carrying current are arranged as shown in the figure. The force experienced by a $25\, cm$ length of wire $C$ is

In the given diagram, the loop tends to:

Give the uses of electromagnets.

$A$ straight wire is placed in a magnetic field that varies with distance $x$ from the origin as $\vec{B} = B_0 \left( 2 - \frac{x}{a} \right) \hat{k}$. The ends of the wire are at $(a, 0)$ and $(2a, 0)$ and it carries a current $I$ in the positive $x$-direction. If the force on the wire is $\vec{F} = IB_0 \left( \frac{ka}{2} \right) \hat{j}$,then the value of $k$ is:

Three long,straight parallel wires carrying currents are arranged as shown. The wire $C$ which carries a current of $5.0 \text{ A}$ is so placed that it experiences no force. The distance of wire $C$ from wire $D$ is (in $cm$)