Question

If the ammeter in the given circuit reads 2A, the resistance R is :-

• A. 1 ohm
• B. 2 ohm
• C. 3 ohm
• D. 4 ohm

Answer 1

The correct option is A 1 ohm

The equivalent resistance for resistors 3 and 6 is $R_{36}=\frac{3\times 6}{3+6}=2\Omega$ and voltage across it $=I{R}_{36}=2\times 2=4V$.
Thus, voltage across R $=6-4=2V$ and as the current 2 A passes through R so $R=V/I=2/2=1$ ohm.