Question

Plz solve it............................​

Answer 1

Let the voltage of source is V

Now the equivalent resistance of the circuit is
Req = R + 1.8

We know that,
V = I R

Let before shorting R current in the circuit is I1
and after shorting R current in the circuit is I2

Case 1: - Before shorting
V = I1 x (R + 1.8) ...(1)

Case 2: - After shorting
V = I2 x (1.8) ...........(2)

Comparing (1) and (2)
$I1 \times (R + 1.8) = I2 \times 1.8$
And given that,
I2 = 2(I1)

$I1 \times (R + 1.8) = 2 \times I1 \times 1.8$
$R + 1.8 = 2 \times 1.8$
$R = 1.8 Ω$