Physics 5054 · O Level · Series and parallel circuits
Series and parallel circuits — practice question
Fig. 6.1 presents a circuit with two identical cells, each having e.m.f. $1.5\,\text{V}$, joined in parallel. It also has two ammeters, a thermistor T and two resistors R and S. Ammeter 1 gives a reading of $0.20\,\text{A}$.
(a)[1]
State why ammeter 2 also shows $0.20\,\text{A}$.
(b(i))[3]
The resistances of R and S are $1.5\,\Omega$ and $3.5\,\Omega$, respectively. Calculate the resistance of T.
(b(ii))[3]
The temperature of T rises. Explain why the potential difference (p.d.) across T falls.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The current is the same at all points in a series circuit.” …