Question

A 120-V circuit contains a 20.0-Ω resistor and a 40.0-Ω resistor connected in parallel.
a) What is the current through the 40.0-Ω resistor?
b)What is the total current in the circuit

Answer 1

a) The potential difference across 40 Ω resistor is 120 V.

Hence, the current through 40 Ω is = $\(\frac{120}{40}\)$

Current through 40 Ω: (I) = 3 A

b) The potential difference across 20 Ω resistor is 120 V.

Hence, the current through 20 Ω is = $\(\frac{120}{20}\)$

Current through 20 Ω: (I) = 6 A

The total current in the circuit = 6 + 3 = 9 A

Total current = 9 A

Answer 2

R1=20 ,R2=40
so,V=IR
I=V÷R
so,the current I1,through R1 = V/R1
so, I1=120÷20 = 6 ,
I2 = 120÷40 = 3
so, total current I = I1 +I2
= 6+3= 9A and
current through 40 R = 3A