$A$ uniform electric field and a uniform magnetic field are produced,pointing in the same direction. An electron is projected with its velocity pointing in the same direction.

Two infinitely long straight wires $A$ and $B$, each carrying current $I$, are placed on the $x$ and $y$-axes, respectively. The current in wires $A$ and $B$ flows along $-\hat{i}$ and $\hat{j}$ directions, respectively. The force on a charged particle having charge $q$, moving from position $r = d(\hat{i} + \hat{j})$ with velocity $v = v\hat{i}$ is:

$A$ uniform magnetic field acts at right angles to the direction of motion of electrons. As a result,the electron moves in a circular path of radius $2\, cm$. If the speed of the electrons is doubled,then the radius of the circular path will be.....$cm$.

$A$ monoenergetic beam of electrons moving along the $+y$ direction enters a region of uniform electric and magnetic fields. If the beam goes straight undeflected,then fields $B$ and $E$ are directed respectively along:

The following figure shows the path of an electron that passes through two regions containing uniform magnetic fields of magnitudes $B_1$ and $B_2$. Its path in each region is a half-circle. Choose the correct option.

$A$ charged particle is released from rest in a region of uniform electric and magnetic fields which are parallel to each other. The particle will move on a