WAEC - Physics (2017 - No. 37)
A circuit is set up as shown in the diagram above. When the key is closed, the ammeter reading will be
6A
4A
2A
1A
Vysvetlenie
The resistors are connected both in parallel and series. To calculate the total resistance, we have:
For the parallel connection: \(\frac{1}{R} = \frac{1}{1} + \frac{1}{1}\)
\(\frac{1}{R} = 2 \implies R = 0.5\Omega\)
For the series connection: \(R_{total} = (1 + 0.5)\Omega = 1.5\Omega\)
Recall, \(V=IR\)
\(3 = 1.5I \implies I = \frac{3}{1.5} =2A\)