Question

The potential difference between $A$ and $B$ in the circuit shown in figure will be

• A. $1V$
• B. $2V$
• C. $3V$
• D. $4V$

Answer 1

Answer: (D)

The resultant e.m.f of the circuit is given by

$ϵ={ϵ}_1-{ϵ}_2$

$=10-5=5V$

Also the resultant resistance of the circuit is given by,

$R_{eq}=2.5+2.5+5+25+15$

$=50\Omega$

So, the current $I$ through the circuit is given by,

$I=\frac{V}{R}=\frac{5}{50}=0.1A$

As all the resistors are in series potential decreases among all of them according to their resistance, which is shown in figure

$V_A=0.25V,V_B=4.25V$

The potential difference between these two points will be,

$V=V_B-V_A$

$=4.25-0.25$

$=4V$