CIE iGCSE Co-Ordinated Science P4.3.2 Series and parallel circuits Exam Style Questions Paper 4
Question
A student is investigating electrical circuits.
(a) Fig. 12.1 shows a circuit made by the student.
(i) The ammeter in Fig. 12.1 reads 0.50A.
The voltmeter in Fig. 12.1 reads 2.0V.
Calculate the resistance of the resistor labelled R in Fig. 12.1.
resistance = ……………………… Ω
(ii) The student notices that resistor R gets hot if the circuit is left connected for too long.
Describe, in terms of current, how the student prevents resistor R from overheating using the circuit shown in Fig. 12.1.
(b) The student replaces the 6.0V battery with a small solar cell.
The solar cell has an efficiency of 16%.
Calculate the power input to the solar cell when the solar cell provides 8.0W of power to the circuit.
power input = ……………….. W
▶️Answer/Explanation
Ans :
12(a)(i) (V=) 6.0 – 2.0 / 4.0 ;
(R =) V / I OR 4.0 / 0.50 ;
(R =) 8.0 (Ω) ;
12(a)(ii) increase the (total) resistance / decrease the current ;
by using the variable resistor ;
12(b) (power input =) power output / efficiency × 100 / 8.0 / 0.16 ;
(power input =) 50 (W) ;