electrical components Flashcards
what happens when a voltage across a component is increased?
the current in the component also increases.
what is a diode?
a component that only allows current to pass in one direction.
what happens to a diode if a voltage is applied in the reverse direction?
it has a very high resistance and prevents any current.
explain an experiment on how to investigate the electrical characteristics of a component.
1) start with a low voltage then slowly increase
2) record the readings of the voltmeter and ammeter as you do
3) repeat the experiment three times and take an average.
define resistance
a measure of a components opposition to current.
what happens when the resistance (for a given voltage) of a circuit increases?
the current around the circuit will decrease (vice-versa).
what is a thermistor (thermal resistor)?
a component which changes its resistance in response to temperature.
what happens when a thermistor is heated?
its resistance decreases (vice-versa)
what is a light dependent resistor (LDR)?
a component which changes its resistance in response to light levels.
what happens if more light is shone on an LDR?
its resistance decreases (vice-versa)
define lamps and light emitting diodes (LED)
components that light up when a current passes through them.
LEDs only allow current to pass in one direction through them and will only light if the current passes in that direction
LEDs only allow current to pass in one direction through them and will only light if the current passes in that direction
what is the equation for voltage?
voltage (V) = current (I) x resistance (R)
what is the unit for resistance?
ohm
