Question

Find the currents $I_1$ and $I_2$ in the given circuit .

• A. $1/15A,1/30A$
• B. $1/10A,1/10A$
• C. $1/30A,1/15A$
• D. $2A,1A$

Answer 1

The correct option is A $1/15A,1/30A$

Total resistance in the circuit is, The resistance in the upper part,

$R_{eq}=R_1+R_2=60\Omega$

Now this resistance is in parallel with the $30\Omega$

so, total resistance given by,

$\frac{1}{R_T}=\frac{1}{R^{}eq}+\frac{1}{R_2}$

$\frac{1}{R_T}=\frac{1}{60}+\frac{1}{30}$

$R_T=20\Omega$

Therefore, current in the circuit is,

$I=\frac{V}{R}=\frac{2}{20}=\frac{1}{10}A$

As voltage in parallel remain the same,

$I_1=\frac{2}{30}=\frac{1}{15}A$

And ,

$I=I_1+I_2$

$\frac{1}{10}=\frac{1}{15}+I_2$

$I_2=\frac{1}{30}A$