# Electronics - Parallel Circuits - Discussion

Discussion Forum : Parallel Circuits - General Questions (Q.No. 25)

25.

Which component is open?

Discussion:

17 comments Page 1 of 2.
LAKHAN said:
4 years ago

Thanks for explaining @Mani.

Mani said:
6 years ago

Here we have a total current of the 21m amp,

Current across R1is.

I1=v/R1=12/1*10^3=12m amp

Current across R2 is;

I2=v/R2=12/2*10^3=6m amp,

Remaining current is 3m amp.

Then current across R4 is,

I3=v/R4=12/2*10^3=3m amp,

Hence resistor R3 is open circuit.

Current across R1is.

I1=v/R1=12/1*10^3=12m amp

Current across R2 is;

I2=v/R2=12/2*10^3=6m amp,

Remaining current is 3m amp.

Then current across R4 is,

I3=v/R4=12/2*10^3=3m amp,

Hence resistor R3 is open circuit.

Naveen said:
7 years ago

Perfect explanation, Thanks.

(1)

Hima.V.M said:
8 years ago

It's a clear explanation, Thank you @Deepti.

Priya said:
10 years ago

@Kishu is right. We can't connect volt and ammeters directly because their will be short circuit.

Suresh b said:
1 decade ago

1 amp = 1000 mA.

0.021 A = 21 mA.

0.021 A = 21 mA.

Aneel said:
1 decade ago

How to calculate total current?

JAGANADHAN.R said:
1 decade ago

Hi,

Total current = 21mA.

Current required by R1 and R2 = 18mA.

So for remaining 3mA(21mA -18mA), R4 = 4K is enough no need for R3.

Thank you.

Total current = 21mA.

Current required by R1 and R2 = 18mA.

So for remaining 3mA(21mA -18mA), R4 = 4K is enough no need for R3.

Thank you.

Subedar Sk shakya said:
1 decade ago

As we know in parallel circuits current divides& voltage remains same here the first amp meter shows 0.021A is the total current flowing through the R1,R2,R3,R4 and second one shows the current flowing through R3&R4

Now current reading for first one r1*r2/r1+r2=1*2/1+2 =2/3 I=V/R so(12)/(2/3)= 18ma now remains 3ma for second one so it clearly shows again I= V/R =12/4k=3ma So no need of R3.

Here R3 is Open.

Now current reading for first one r1*r2/r1+r2=1*2/1+2 =2/3 I=V/R so(12)/(2/3)= 18ma now remains 3ma for second one so it clearly shows again I= V/R =12/4k=3ma So no need of R3.

Here R3 is Open.

Saurabh said:
1 decade ago

This is not clear how R3 is open connection means only one pole is connected.

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