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What is light?
Nature of light unit 5.1 - revision with Alex Monk
| Question | Answer |
|---|---|
| E=hf is an equation you must be able to recognise and use. What does each letter stand for? | E = Energy of photons; h = Planck's constant; and f = Wave frequency |
| When E=hf, what is the unit of 'h'? | Js^-1 |
| What is radiation flux a measure of? | It is a measure of how intensely light shines on something |
| Flux = power/area. Give the unit of 'flux'? | Wm^-2 |
| State one application of Gamma waves | Sterilising medical equipment is an example of an application... |
| Name one detector of X-Rays | Photographic films |
| The absorption of a photon can result in the emission of a photoelectron. What is the name of this 'effect'? | The photoelectric effect! |
| For a given surface, there is a minimum frequency of light below which no emission of photoelectrons occurs. What is this frequency known as? | Threshold frequency |
| eV - what does this non-SI unit stand for? | Electronvolt |
| On a negatively charged electroscope, what effect does UV light have on the gold leaf? | The gold leaf falls (immediately) |