Question

What is the voltage lost to the 20 ohm resistor?

Answer 1

From the question, the voltage of the source, V =20 V

The total resistance of the circuit is, R=20 Ω+30 Ω+40 Ω=90 Ω

According to Ohm's law, V=IR

Where I is the current in the circuit.

Substituting the values of V and R,

$20=I\times90$

Which gives us

$I=\frac{20}{90}=0.22\text{ A}$

Now we calculate the voltage across 20 Ω resistor.

We use Ohm's law again, but we will substitute R=20 Ω as we are calculating the voltage across the 20 Ω resistor.

$V_{20}=0.22\times20=4.4\text{ V}$

That is voltage lost across the 20 Ω resistor is 4.4 V