Cambridge Secondary (7-9). Stage 9. Science. Learner's Book - Unit 9: Electricity

Question 95

Look at the circuit diagram. What can this circuit be used for? Write one letter.

Question illustration

Changing the loudness of the buzzer, keeping the brightness of the lamp constant.
Changing the brightness of the lamp, keeping the sound from the buzzer constant.
Changing the loudness of the buzzer and brightness of the lamp at the same time.
Changing the loudness of the buzzer and brightness of the lamp separately.