1. What is the magnitude of the electrical force acting on the proton in a hydrogen atom from the atom's electron? (To answer this question you must find the radius of a hydrogen atom.)

2. If the electric field from an alpha particle is 115 N/C how far away is the alpha particle?

3. An object with a +2.0 C charge of is 3.0 m east of an object with -3.0 C charge and 4.0 m south of another object with +5.0 C charge. What is the net electrical force on the +2.0 C charged object?

4. An electron is accelerated from rest by two charged plates that have an electrical potential of 120 V. Calculate the kinetic energy gained by the electron when it reaches the far plate in J and eV and then determine the speed of the electron at that location.

5. Two charged plates are 1.0 cm apart and have an electrical potential of 3.0 kV between them. An electron travelling 5.0 x 104 m/s passes through at right angles to the plates and exactly halfway between them. If the plates are 2.5 cm long in the direction the electron is moving, will the electron pass through or will it collide with the positive plate? Show how you reached your conclusion.

6. The north pole of a compass needle points away from one end of a permanent magnet. Use this information to draw that end of the magnet. On your picture show; i) The polarity of that end of the magnet ii) One magnetic field line at that end of the magnet.

7. An alpha particle travelling 500 m/s west is accelerated upwards at 7.20 x 105 m/s2 by the earth's magnetic field. How strong is the magnetic field at that location?

8. A wire in an electric motor is carrying 20.0 A. If the magnetic field in the motor is 25.0 T, what length of wire has to be in the magnetic field to produce a force of 500 N?