Question

The current that passes through 20 ohm resistance when it is connected in parallel with a 30 ohm resistance and this set is connected to a battery of 2V is

• A. 0.2A
• B. 0.016A
• C. 0.3A
• D. 0.1A

Answer 1

Answer: (D)

The situation is shown in the figure. The total resistance in the circuit is 12ohm. So the total current flowing through the circuit is $I=2/12=1/6A$.
Let the current passing through the 20 ohm resistance be $i_1$ and that through the 30 ohm resistance be $i_2$.
Thus we get:
$i=i_1+i_2$ and $20i_1=30i_2$
Thus we get:
$i_1+\frac{2}{3}{i}_1=\frac{1}{6}$
or
$i_1=0.1A$