Question

A current of 2 A flows in an electric circuit as shown in figure. The potential difference $(V_R-V_S)$, in volts will be :

• A. $-4$
• B. $+2$
• C. $+4$
• D. $-2$

Answer 1

The correct option is C $+4$

As both the arms have equal resistance of $3+7=10\Omega$, current gets equally distributed.

So current in each arm is $1A$.

So, $V_R-V_Q=1A\times 7\Omega =7V$

and, $V_S-V_Q=1A\times 3\Omega =3V$

Thus, $(V_R-V_Q)-(V_S-V_Q)=V_R-V_S=7V-3V=4V$