The energy change in a thermocouple is :

1
The energy change in a thermocouple is

• EE to EH
• ES to EE
• EL to EE
• EH to EE

2
The resistance of an LDR

• Increases as temperature decreases
• Decreases as light level decreases
• Increases as light level decreases
• Decreases as temperature increases

3
The resistance of the LDR is

• 0.05 ?
• 500 ?
• 20 ?
• 0.02 ?

5 V
10 mA
0 V
4
When a capacitor charges up

• The voltage across it decreases but the charge
  stored increases
• The voltage across it increases and the charge
  stored increases
• The voltage across it decreases and the charge
  stored decreases
• The voltage across it increases and the charge
  stored decreases

5
The correct input device to supply a time delay
is

• Solar cell
• Microphone
• Thermistor
• Capacitor

6
The voltage across the 20? resistor is
5 V

• 5 V
• 4V
• 1V
• 25 V

80? 20?
0 V
7
To decrease the time delay in an alarm circuit
you would

• Increase the capacitance
• Decrease the capacitance
• Increase the resistance

Vout
8
What happens to Vout as light level falls ?

• Vout increases as RLDR decreases
• Vout decreases as RLDR decreases
• Vout increases as RLDR increases
• Vout decreases as RLDR decreases

5 V
Vout
0 V
9
What happens to Vout as temperature increases ?

• Vout decreases as Rth increases
• Vout decreases as Rth decreases
• Vout increases as Rth decreases
• Vout increases as Rth increases

5 V
Vout
0 V
10
Explain what happens to Vout when the current is
switched on

• Vout decreases as the capacitor discharges
• Vout increases as the capacitor charges
• Vout increases as the capacitor discharges
• Vout decreases as the capacitor charges