A deuteron and a proton moving with equal kinetic energy enter into to a uniform magnetic field at right angle to the field. If $r_{d}$ and $r_{p}$ are the radii of their circular paths respectively, then the ratio $\frac{r_{d}}{r_{p}}$ will be $\sqrt{ x }: 1$ where $x$ is ..........

An electron is projected normally from the surface of a sphere with speed $v_0$ in a uniform magnetic field perpendicular to the plane of the paper such that its strikes symmetrically opposite on the sphere with respect to the $x-$ axis. Radius of the sphere is $'a'$ and the distance of its centre from the wall is $'b'$ . What should be magnetic field such that the charge particle just escapes the wall

A charged particle is moving with velocity $v$ in a magnetic field of induction $B$. The force on the particle will be maximum when

Maximum kinetic energy of the positive ion in the cyclotron is

An electric field of $1500\, V/m$ and a magnetic field of $0.40\, weber/metre^2$ act on  a moving electron. The minimum uniform speed along a straight line the electron could  have is

An electron moving with a uniform velocity along the positive $x$-direction enters a magnetic field directed along the positive $y$-direction. The force on the electron is directed along