AQA A level Physics Paper 1

AQA A level Physics Paper 1 Current - ANS Rate of flow of charge Coulomb - ANS The amount of charge passing a point when a current of 1A flows for 1s Potential difference - ANS The work done per unit charge in moving a small point positive charge between two points Threshold Voltage for a Diode - ANS The voltage at which a current will begin to flow at, assumed to be +0.6V if not stated Reverse Bias - ANS When very little currency can flow in the reverse direction of a diode Variable Resistor - ANS Can be used to change the current through a circuit can also be called a rheostat NTC Thermistor - ANS (A type of semiconductor) that has decreasing resistance when its temperature increases - negative temperature coefficient Transitional Temperature - ANS The critical temperature at and below which a superconductor has zero resistivity Semiconductor - ANS A group of materials which conduct electricity (not as well as metals), when their temperature rises they can release more charge carriers and their resistance decreases Resistance - ANS The ratio of a components potential difference to its current Volt - ANS The potential difference across a component when 1 joule of energy is used to move a coulomb of charge through a component Ohm's Law - ANS Provided that the physical conditions remain the same, the current through an ohmic conductor is directly proportional to the potential difference across it