# Electrical Engineering - Parallel Circuits - Discussion

Discussion Forum : Parallel Circuits - General Questions (Q.No. 2)
2.
The total resistance of a parallel circuit is 50 . If the total current is 120 mA, the current through the 270 resistor that makes up part of the parallel circuit is approximately
22 mA
120 mA
220 mA
50 mA
Explanation:
No answer description is available. Let's discuss.
Discussion:
15 comments Page 1 of 2.

According to current div rule.

Current= (total current*total resistance) /particular resistance.

Thanks raja.

Acc to CDR, current = (particular resistance * total current)/total resistance..

Can be explain anybody ?

Total Resistance=50
R1 and R2 are in parallel.
(1/R1)+(1/R2)=(1/50)
R1=270 ohms (given)
R2=61.36
R2=R1/(m-1)
where m=(Total Current/Current through 270 ohms)
Using above formula find out the current through 270 ohms...

Parampal sehgal said:   1 decade ago
120 ma * 50/270 = 22ma
(1)

Concept of raja and ramesh wrong, Sehegal is correct.
Try this way:
Total voltage = 50ohm * 120mA = 6 V
Current through 270 ohm resistor = 6 V/270 ohm = 22 mA

MOHIT RAJHANS said:   1 decade ago
R1 and R2 are in parallel,

So (R1) * (R2) / (R1+R2) =50.

R1 = 270 ohm, R2 is unknown.

We get R2 = 61. 3 ohms.

Now using current division rule we get,

I2 = (Total current) * (R2/R1+R2).

= 120* (61/331).

= 22 mA.

That is the required answer, hope you people understand.

Mrakovic said:   10 years ago
Ri = 50ohm.

Ii = 120 mA = 0.120A.

R1 = 270 ohm.

U = Ii*Ri = 0.120*50 = 6V.

I1 = U/R1 = 6/270 = 0.022A = 22 mA.

Shiva said:   9 years ago
R1 = 50 ohm.
I1 = 120 mA.
V = I*R(50*120 = 6000 mV).
I2 = V/R2 = 6000/270
= 22.22 mA.