Question

Calculate the unknown resistance R of the circuit as shown in figure, all resistance are connected in the series. The current is flowing through circuit is 2A and battery is of 20 voltage.

• A. $1\Omega$
• B. $2\Omega$
• C. $4\Omega$
• D. $6\Omega$
• E. $12\Omega$

Answer 1

The correct option is B $2\Omega$

Given : $V=20$ volts $I=2$ A

Total resistance of the circuit $R_{eq}=R+4+4=R+8$

Using $V=I{R}_{eq}$

$\therefore$ $20=2(R+8)$ $⟹R=2\Omega$