Question

A circuit shows two resistors whose resistance are 0.40ohms and 0.60ohms connected in parallel. They are part of a circuit which carries a current I, and the current in the 0.40ohms resistor is 1.50A

Calculate:
1) The current in the circuit
2) The current in the 0.60ohm resistor

Answer 1

The voltage, at the resistance of 0.40 Ohm is calculated using Ohm's Law.

$V_{0.40\Omega}=I_{0.40\Omega}*R$

• Where

Electric resistance $R=0.40\Omega$

Electric current $I_{0.40\Omega}=1.50A$

Numerically evaluating $V_{0.40\Omega}=1.50A*0.40\Omega=0.60V$

As it is a parallel circuit, the voltage across all resistors is the same, that is.

$V_{0.40\Omega}=V_{0.60\Omega}=0.60V$

Now, calculating the current by the resistance of 0.60Ohm using ohm's law

$I_{0.60\Omega}=\frac{V_{0.60\Omega}}{R}$

• Where

Voltage $V_{0.60\Omega}=0.60V$

Resistance $R=0.60\Omega$

Numerically evaluating $I_{0.60\Omega}=\frac{0.60V}{0.60\Omega}=1.0A$

Finally

Question (a)

The current that passes through the circuit is

$I=I_{0.40\Omega}+I_{0.60\Omega}=1.50A+1.0A=\boxed{2.5A}$

Question (b)

The current passing through the resistance of 0.60Ohm is

$I_{0.60\Omega}=\boxed{1.0A}$