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GCSE SCIENCE PHYSICS
Electricity and Waves
Question | Answer |
---|---|
Define electromagnetic induction: | The creation of a VOLTAGE (and maybe a current) in a wire which is experiencing a CHANGE IN MAGNETIC FIELD. |
How can a voltage be induced in a conductor? | By moving a magnet in or near coil of wire. |
What are the four factors that affect the size of the induced voltage and current? | The strength of the magnet The area of the coil The number of turns on the coil The speed of the movement |
Define amplitude: | The distance from rest to crest and rest to trough |
Define wavelength: | The distance between crest to crest |
Define frequency: | Number of complete waves passing a certain point per second Number of complete waves produced by a source each second |
What is frequency measured in? | Hertz(Hz) |
What does 1Hz equal? | 1 wave per second |
Are most waves transverse or longitudinal? | Transverse |
Give an example of a transverse wave: | Light Any electromagnetic waves |
True or false? In transverse waves the vibrations are parallel to the direction of energy transfer of the wave? | False The waves are perpendicular to the direction of energy transfer of the waves |
What does S=F*W stand for? | Speed = Frequency * Wavelength (m/s) (Hz) (m) |
What i the direction of vibrations in longitudinal waves? | Perpendicular to direction of energy transfer of the wave. |
Give an example of a longitudinal wave: | Sound waves Ultrasound Shock waves (e.g. seismic waves) |
What is the law of reflection? | Angle of incidence = angle of reflection |
What is the imaginary line that is perpendicular to the surface at the point of incidence? | The normal |
State how much diffraction occurs for each of the following: 1) Gap is much wider than the wavelength 2) Gap is the same as the wavelength 3) Gap is a bit wider than the wavelength | 1)Little diffraction 2)Maximum diffraction 3)Diffraction only at the edges |
When a light wave goes from less dense to dense it will... | Slow down |
When light goes through a boundary (less dense to dense) what changes and what stays the same? | The frequency stays the same The wavelength shortens |
If a wave hits a boundary (less dense to dense) at an angle it will slow down and change direction. What does the change in direction show? | Refraction |
True of false? When light slows down if refracts towards the normal | False When light slows down it refracts away from the normal |