A-level Physics (Advancing Physics)/Electric Potential/Worked Solutions

ε0 = 8.85 x 10−12 Fm−1

1. Draw a diagram of a uniform electric field between two plates, showing the field lines and the equipotentials.

Field lines equipotentials parallel plates.svg

2. Do the same for the electric field around a point charge.

Electric field point lines equipotentials.svg

3. The potential difference between two plates is 100V. What is the potential difference between a point halfway between the plates and one of the plates?

Half of 100 is 50V.

4. What is the electric potential at a point 0.2m from an alpha particle (charge on an electron = -1.6 x 10−19C)?

The charge on an alpha particle is 3.2 x 10−19C.

5. What is the electric potential energy of an electron at the negative electrode of an electron gun if the potential difference between the electrodes is 10V?