Consider the mass-spectrometer as shown in figure. The electric field between plates is $\vec E\ V/m$ , and the magnetic field in both the velocity selector and in the deflection chamber has magnitude $B$ . Find the radius $'r'$ for a singly charged ion of mass $'m'$ in the deflection chamber 

In a chamber, a uniform magnetic field of $6.5 \;G \left(1 \;G =10^{-4} \;T \right)$ is maintained. An electron is shot into the field with a speed of $4.8 \times 10^{6} \;m s ^{-1}$ normal to the field. Explain why the path of the electron is a circle. Determine the radius of the circular orbit.

$\left(e=1.5 \times 10^{-19} \;C , m_{e}=9.1 \times 10^{-31}\; kg \right)$

If a proton enters perpendicularly a magnetic field with velocity $v$, then time period of revolution is $T$. If proton enters with velocity $2 v$, then time period will be

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

Ratio of electric and magnetic field due of moving point charge if its speed is $4.5 \times 10^{5} \;m / s$

Bob of a simple pendulum of length $l$ is made of iron . The pendulum is oscillating over a horizontal coil carrying direct current. If the time period of the pendulum is $T$ then