Sensor Circuits Quiz - 13.5 IGCSE Physics

What is the function of a thermistor in a temperature sensor circuit?

• No effect on temperature

• Remains constant with temperature

• Decreases resistance with temperature

• Increases resistance with temperature

What happens to the output potential difference in a light sensor circuit when the brightness of the incident light increases?

• Remains constant

• Decreases

• Increases

• Becomes zero

What is the purpose of a potential divider in a sensor circuit?

• To decrease resistance

• To measure current

• To increase resistance

• To control the output potential difference

What is the action of a variable potential divider in a sensor circuit?

• Increases resistance with temperature

• Decreases resistance with temperature

• Remains constant with temperature

• No effect on temperature

In a potential divider, what is the relationship between the resistor pds and their resistances?

• Inversely proportional

• Opposite relationship

• Directly proportional

• No relationship

What is the purpose of a potentiometer in a sensor circuit?

• To measure resistance

• To control the output potential difference

• To increase current

• To decrease current

In Figure 13.5.2, why does the output pd decrease when the LDR is covered completely so it is in darkness?

• The resistance of the thermistor decreases

• The resistance of the thermistor increases

• The resistance of the LDR decreases

• The resistance of the LDR increases

In the new circuit diagram where the thermistor and the resistor are swapped, how does the output pd change when the temperature of the thermistor is reduced?

• Increases

• Decreases

• Remains constant

• No effect

In a potential divider consisting of a 20Ω resistor in series with a 30Ω resistor connected to a 5.0V battery, why is the pd across the 30Ω resistor greater than the pd across the 20Ω resistor?

• Higher resistance

• Lower resistance

• Higher current

• Lower current

What is the current through the battery and the pd across the 30Ω resistor in the potential divider circuit?

• 0.2A and 5.0V

• 0.1A and 1.0V

• 0.2A and 2.0V

• 0.1A and 4.0V