Components

Question 1

A voltmeter is … and measures …
The symbol for a voltmeter is :

Answer 1

• Added in parallel to the circuit.
• Potential Difference (V)

Question 2

An ammeter is … and measures …
The symbol for an ammeter is :

Answer 2

• Connected in series with the circuit.
• Current (A)

Question 3

An LED (light emitting diode) will …

The symbol for an LED is :

Answer 3

• Only let current flow through it in one direction.
• Emit light when current flows through it.

Question 4

What happens to the resistance in an LDR when light intensity increases?

The symbol for an LDR is :

Answer 4

The resistance decreases, so more current can flow.

Question 5

Explain the uses of an LDR.

Answer 5

An LDR is useful in burglar alarms and automatic night-lights,
Because the resistance will decrease,
So current can flow and power the devices.

Question 6

Describe the effect of an increase in temperature on the resistance of a thermistor.

The symbol for a thermistor is :

Answer 6

As temperature increases, the resistance in a thermistor decreases, so more current can flow.