CAIE IGCSE Physics 4.3.2.3 Combined e.m.f. of several sources in

Practise adding cell e.m.f.s in series and working backwards from a battery voltage to find the e.m.f. or number of cells.

Exam points

calculate total e.m.f. by adding cell or battery voltages in series
determine the number of identical cells from a battery e.m.f. and one cell's e.m.f

[Maximum number: 1]

Fig. 8.2 shows a circuit.

Fig. 8.2

The three cells are identical and have zero resistance.
The resistors $R_{1}, R_{2}$ and $R_{3}$ are identical.
The reading on the voltmeter is 6.0 V .
When the diode is conducting, it has zero resistance and zero potential difference (p.d.) across it.

Determine the e.m.f. of one cell.

e.m.f. =

All question bank results loaded

4.3.2.3—Combined e.m.f. of several sources in question 1