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The value of current in the 6 Ω resistance is [Figure: a 140 V battery on the left and a 90 V battery on the right, both with positive terminal up and negative terminal on the common bottom wire. From the top of the 140 V battery a 20 Ω resistor leads to a top junction X; from X a 5 Ω resistor leads to the top of the 90 V battery; a 6 Ω resistor joins X to the bottom wire.]

Asked in JEE Main 20th July 1st Shift 2021 · Kirchhoff's laws in networks

Figure: Kirchhoff's laws in networks
Answer: (4) 10 A

Step-by-step solution

Let the potential of X be V (bottom wire at 0).

KCL at X: (140-V)/(20)+(90-V)/5=V/6.

Multiply by 60: 420-3V+1080-12V=10V, so V=60 V.

Current in 6 Ω =(60)/6=10 A.

Why the other options are wrong

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