P4 Revision

Question 1

What is a diode?

Answer 1

a non-ohmic conductor that has a much higher resistance in one direction (its reverse direction) than in the other direction (its forward direction)

Question 2

What is an electron?

Answer 2

tiny negatively charged particles that move around the nucleus of an atom

Question 3

What is an
light-depending resistor (LDR)?

Answer 3

a resistor whose resistance depends on the intensity of the light incident on it

Question 4

What is an light-emitting diode (LED)?

Answer 4

a diode that emits light when it conducts

Question 5

What is Ohm’s law?

Answer 5

the current through a resistor at constant temperature is directly proportional to the potential difference across the resistor

Question 6

What is parallel?

Answer 6

components connected in a circuit so that the potential difference is the same across each one

Question 7

What is potential difference?

Answer 7

a measure of the work done or energy transferred to the lamp by each coulomb of charge that passes through it. The unit of potential difference is the volt (V)

Question 8

What is resistance?

Answer 8

resistance (in ohms, Ω) = potential difference (in volts, V) ÷ current (in amperes, A)

Question 9

What is a series?

Answer 9

components connected in a circuit in such a way that the same current passes through them

Question 10

What is a thermistor?

Answer 10

a resistor whose resistance depends on the temperature of the thermistor