Electrical Engineering - Parallel Circuits - Discussion

Discussion :: 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

[A]. 22 mA
[B]. 120 mA
[C]. 220 mA
[D]. 50 mA

Answer: Option A

Explanation:

No answer description available for this question.

Raja said: (Feb 25, 2011)  
According to current div rule.

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

Deva said: (Aug 26, 2011)  
Thanks raja.

Mohana.. said: (Aug 27, 2011)  
Acc to CDR, current = (particular resistance * total current)/total resistance..

Dilip said: (Nov 20, 2011)  
Can be explain anybody ?

Ramesh said: (Jan 26, 2012)  
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: (Mar 12, 2012)  
120 ma * 50/270 = 22ma

Sarkars said: (Jul 26, 2012)  
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: (Nov 23, 2012)  
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: (Sep 24, 2013)  
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: (Oct 17, 2014)  
R1 = 50 ohm.
I1 = 120 mA.
V = I*R(50*120 = 6000 mV).
I2 = V/R2 = 6000/270
= 22.22 mA.

Abd said: (Jun 14, 2015)  
I think we can do by ohm's also. In first case we know resistance value and current by this we can find voltage value. In second case we we know resistance value and we already find voltage in first case by using these we can find current.

Ex : Case 1:

V = IR.
V = 50*120 ma.
V = 6 volt.

Case 2:

I = v/r.
I = 6/270.
I = 22 ma.

Let me know this method is correct or not.

Sindhu said: (Jun 22, 2015)  
@Abd.

This method can be used as you have the total resistance as 50 ohm and total current as 120 mA given.

Puja said: (Jan 19, 2017)  
I can't understand. Someone explain me clearly.

Azeem said: (Jul 3, 2017)  
Voltage division For Series Circuits.
Vr = (R/Req) * V.

Current Division for parallel circuit
Ir = (Req/R) * I.

Where Req is the equivalent resistance (either series or parallel.
R is the resistance for which you want to determine the voltage or current.
Ir and Vr are the current and voltage respectively of the resistor in question.
I and V are the current and voltage respectively to be divided.

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