Q 12-03-226JEE MainJEE Main 2020 (7 Jan, Shift 1)Easy
The current $I_1$ (in A) flowing through the $1\ \Omega$ resistor in the following circuit is:
Answer: (C) $0.2$
The ideal $1$ V cell is connected directly across both the $2\ \Omega$ resistor and the upper branch, so each branch has $1$ V across it.
Upper branch: the two $1\ \Omega$ resistors in parallel ($0.5\ \Omega$) in series with $2\ \Omega$, total $2.5\ \Omega$. Its current is $\dfrac{1}{2.5} = 0.4$ A.
This divides equally between the two identical $1\ \Omega$ resistors:
$$I_1 = 0.2\ \text{A}$$
Solution by Sreeraj P, M.Sc Physics