A circuit is set up as shown in the diagram above. When the key is closed, the ammeter reading will be
Attached Figure / Diagram
A
6A
B
4A
C
2A
D
1A
Verified Correct Answer: C.
Physical Principles & Numerical Solution
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, \(V=IR\)
\(3 = 1.5I \implies I = \frac{3}{1.5} =2A\)
Source: Myschool Past Questions Archive (Record #50045)