1) An electron moves in a circular orbit perpendicular to a uniform magnetic field. A second electron is also moving in a circular orbit in the same magnetic field with twice the radius.

How do the period of revolution and the speed of the second electron compare with those of the first?

2) The diagrams show different particle beams entering a region between two metal plates in which there are uniform electric and magnetic fields.

In which arrangement would it be possible for the beam to pass through undeflected?

3) A charge Q is travelling with speed v in a magnetic field B. At one instant in time, its velocity is at an angle θ to the horizontal as shown.

What is the magnetic force acting on it at this instant in time?

4) P and Q are two ions with masses m_P and m_Q respectively. They have the same charge q and the work done on both charges after passing through an applied p.d. of V is qV. Subsequently, P and Q enter a magnetic field B.

The radius of the path of ions P and Q is r_P and r_Q respectively. What is the ratio of r_Q / r_P?

5) A particle of mass m and charge +q enters with speed v at right angles to a magnetic field B. The particle arrives at point P, a distance d from the slit as shown in the diagram below.

Which of the following is a correct expression for d?