Current Electricity

Question 1

Current

Answer 1

The rate of flow of charge (Amps)

Question 2

Coulombs

Answer 2

Unit of charge

Question 3

Ohm’s Law

Answer 3

Current is proportional to voltage (potential difference) provided temperature is kept constant

Question 4

Potential Difference

Voltage

Answer 4

Current x Resistance

V = IR

Question 5

Voltmeter

Answer 5

Placed across a device in parallel to measure potential difference

Question 6

Resistors placed in series

Answer 6

Adding resistors in series increases the resistance and decreases current

Question 7

Resistors in parallel

Answer 7

Adds another path for current to travel → current from battery increases

Question 8

I-V graph for filament lamp

Answer 8

Not a straight line through the origin → filament lamps don’t obey Ohm’s Law

Decreasing Gradient

Question 9

Resistance in a filament lamp

Answer 9

Increases because the lamp heats up → more vibrations of metal ions (more resistance)

Question 10

LDR

photoresistor

Answer 10

Resistance decreases as light intensity increases

Question 11

Thermistor

Answer 11

Resistance decreases as temperature increases