| Explain what is meant by the principle of relativity. | [1] |
| If we combine the Galilean transformation with Maxwell's theory of electromagnetism, we violate the principle of relativity. Explain why this is so. | [1] |
| What is the equivalence principle? Explain why the equivalence principle implies that light should be deflected by a gravitational field. How was this effect first used to test general relativity? | [3] |
(2005 Q1.)