CIE iGCSE Co-Ordinated Science P4.3.1 Circuit diagrams and circuit components Exam Style Questions Paper 1
Question
In which circuit can the brightness of the lamp be varied continuously?
▶️Answer/Explanation
Answer: A
Explanation: A variable resistor (rheostat) allows the current in the circuit to be adjusted, which in turn varies the brightness of the lamp continuously.
Question
Which circuit can be used to take measurements to determine the resistance of resistor R?
▶️Answer/Explanation
Answer: D
Explanation: To measure resistance, the voltmeter must be connected in parallel across the resistor to measure the voltage, and the ammeter must be connected in series to measure the current. Ohm’s Law (R = V/I) can then be used to calculate the resistance.
Question
Which circuit shows an ammeter that measures the current in the lamp and a voltmeter that measures the potential difference (p.d.) across the lamp?
▶️Answer/Explanation
Answer: C
Explanation: In Circuit C, the ammeter is correctly placed in series with the lamp to measure the current, and the voltmeter is correctly placed in parallel with the lamp to measure the potential difference across it.
Question
What is represented by the circuit symbol shown?
A fixed resistor
B fuse
C switch
D variable resistor
▶️Answer/Explanation
Answer: D variable resistor
Explanation: The symbol shown represents a variable resistor, which is a resistor whose resistance can be adjusted.
Question
A student connects a circuit to determine the resistance of a resistor.
Which circuit enables the current in the resistor and the potential difference (p.d.) across it to be measured?
▶️Answer/Explanation
Ans :A
Question
Which row shows how lamps are connected in a lighting circuit in a house and gives an advantage of connecting them in this way?
▶️Answer/Explanation
Ans : A
Question
The diagrams show four circuits each containing a motor and two switches. The switches are all open.
In one of the circuits, closing one of the switches on its own starts the motor turning, and closing
the other switch on its own also starts the motor turning.
Which circuit is this?
▶️Answer/Explanation
Ans: A
Question
The diagram shows a 12V battery connected to two 6.0 resistors and a switch.
What is the current in the battery with the switch closed and what is the current with the switch open?
▶️Answer/Explanation
Ans: C
Question
The diagram shows a circuit containing two switches P and Q, and three lamps. One lamp is labelled X.
Which of the switches must be closed so that only lamp X is lit?
A neither switch
B switch P only
C switch Q only
D switch P and switch Q
▶️Answer/Explanation
Answer: D
Explanation: Both switches P and Q must be closed to complete the circuit and allow current to flow through lamp X only.
Question
In the circuit, component X is used to control the brightness of the lamp.
What is component X?
A. an ammeter
B. a fixed resistor
C. a fuse
D. a variable resistor
▶️Answer/Explanation
Answer: D
Explanation: A variable resistor is used to control the brightness of a lamp by adjusting the current flowing through the circuit. This allows for the brightness to be increased or decreased as needed.