A circuit consists of two parallel resistors, having a resistance
| A circuit consists of two parallel resistors, having a resistance of 20 Ω and 30 Ω respectively connected in series with 15 Ω. If the current through the 15 Ω resistor is 3A, then find the current through 20 Ω and 30 Ω resistors respectively.
A. 1 A, 2 A
B. 1.8 A, 1.2 A
C. 1.2 A, 1.8 A
D. 2 A, 1 A
Please scroll down to see the correct answer and solution guide.
Right Answer is: B
SOLUTION
Concept:
By using current division rule,
The current flows through the resistor R1 is \({I_{R1}} = I\left( {\frac{{{R_2}}}{{{R_1} + {R_2}}}} \right)\)
The current flows through the resistor R2 is \({I_{R2}} = I\left( {\frac{{{R_1}}}{{{R_1} + {R_2}}}} \right)\)
Calculation:
The given circuit arrangement is as shown below.
The current flowing through the 20 Ω resistor is
\({I_{20}} = 3\left( {\frac{{30}}{{30 + 20}}} \right) = 1.8\;A\)
The current flowing through the 30 Ω resistor is
\({I_{30}} = 3\left( {\frac{{20}}{{30 + 20}}} \right) = 1.2\;A\)
