A positively charged particle moves in a region having a uniform magnetic field and uniform electric field in same direction. At some instant, the velocity of the particle is perpendicular to the field direction. The path of the particle will be

A rectangular loop carrying a current $i$ is situated near a long straight wire such that the wire is parallel to one of the sides of the loop and the plane of the loop is same of the left wire. If a steady current $I$ is established in the straight wire as shown, the loop will -

A uniform magnetic field $\overrightarrow{B}=\left(3\hat{\mathrm{I}}+4\hat{\mathrm{j}}+\hat{\mathrm{k}}\right)$  exists in the region of space. A semicircular wire of radius $1 \mathrm{m}$ carrying current $1 \mathrm{A}$ having its centre at $(2, 2, 0)$ is placed in-plane$x-y$ plane as shown in fig. The force on the semicircular wire will be

Select the correct alternative(s): 

Two thin long parallel wires separated by a distance $b$are carrying a current $i$ ampere each. The magnitude of the force per unit length exerted by one wire on the other is

In the figure shown a current $I_1$ is established in the long straight wire $\mathrm{AB}$. Another wire $\mathrm{CD}$  carrying current $I_2$ is placed in the plane of the paper. The line joining the ends of this wire is perpendicular to the wire $\mathrm{AB}$. The resultant force on the wire $\mathrm{CD}$ is