Question

Q. find the value of current through 2 ohm resistor (a) 1.0 A (b) 1.5 A (c) 5.0 A (d) 2.1 A

Answer 1

Let x be the voltage at the junction of 10v 20v and 1 ohm respectively.

Apply KCL at the junction.

(x-10)/2 + (x-0)/1 + (x-20)/4 = 0

(2x – 20 + 4x + x – 20 ) = 0

7x = 40

x = 40/7

I = (40/7 – 10)/2 => -30/14 = -15/7A

minus sign indicates that the current is flowing in the opposite direction of that assumed.