Question

Figure shows two electrical circuits.

The batteries in circuit 1 and circuit 2 are
(a) Put ticks in the table below to describe identical. the connections of the two resistors P and Q.

(b) The resistor P and Q are used as small electrical heaters.
State two advantages of connecting them as shown in circuit 2.

(c) In circuit 1, the ammeter reads 1.2A when the switch is closed.  

Calculate the reading of the voltmeter in this circuit.
(d) The two switches in circuit 2 are closed. Calculate the combined resistance of the two resistors in this circuit.
(e) When the switches are closed in circuit 2, ammeter 1 reads 5 A and ammeter 2 reads 2A. Calculate
(i) the current in resistor P,
(ii) the power supplied to resistor Q,
(iii) the energy Transformed in resistor Q in 300s.

Answer 1

(b) (i) If one electrical heater stops working due to some defect then other keeps working normally.
(ii) Each electrical appliance (heater) gets the same voltage (220 V) as that of the power supply line.