In the given circuit diagram, a wire is joining points B and D. The current in this wire is:
(A)zero
(B)2 A✓ Correct
(C)0.4 A
(D)4 A
Answer: (B)
Solution
Reducing the network with Kirchhoff's rules, the branches combine to an effective resistance of 54+56=2Ω, so the 20 V source drives a total current i=220=10 A. When this current splits through the two arms and the junction rule is applied at B, the wire joining B and D carries the difference of the two branch currents, 54i−53i=5i=510=2 A.
JEE Main · 2020 · 09 Jan 2020 · Shift 1 · Single correct option