# Electronics - Parallel Circuits - Discussion

Discussion Forum : Parallel Circuits - General Questions (Q.No. 10)
10.
Which component is shorted?

R1
R2
R3
R4
Explanation:
No answer description is available. Let's discuss.
Discussion:
49 comments Page 2 of 5.

Vishnu said:   9 years ago
A galvanometer is a very sensitive meter which is used to measure tiny currents, usually 1 mA or less. And its symbol is different there is no image shows that current is passing through R4 or R4 act as a load better is to put a volt meter across every resistor to show that the current is passing through to simplify the question.

Ravi said:   9 years ago
Guys, they are asking which of these resistors is faulty (thus creating a shorted path) and they have shown us that no current flows through first three resistors, that means R4 is shorted.

Kevin said:   9 years ago
The way I made sense of this problem is to think of the battery as a voltage source with and internal series resistor not shown.

Short circuit current is 2.4 amps Internal series resistance can be calculated, R=I/V, R=2.4 amps/12 Volts = 0.2 ohms.

The only way to get all 4 ammeters to read 2.4 amps is for R4 to be shorted.

Rashmi said:   9 years ago
If negative terminal of g is connected to battery it don't mean that the g is shorted.

Mamta said:   9 years ago

As we all know, voltage is constant in parallel circuit. So I = V/R.

Current through R1 = 12 mA.

Similarly through R2, R3 and R4 is 6 mA, 4 mA and 3 mA.

Open circuit = No current or less current flows.

Short circuit = Large current flows.

But Large current flow is through. So how can R4 short circuit?

As per this rule R1 should be short circuited as low resistance is R1.

Hey guys G is not a Conductance if its conductance means they denote it as (mho) not by G we have to use its unit only after the values not variables its galvanometer I agree wit pankaj he is right G is galvanometer and it measure current. 2.4 A is in the next G so no current through the R1. Similarly, no current through R2, R3 and finally whole current through R4. So R4 is short circuited and others are open circuit.

Sushama Saroj said:   8 years ago
Those of you who have optioned for R4, as the answer.

Here is my doubt for them as to why R4 was thought as shorted, and why not you guys said that any of the R1, R2 or R3 was shorted and the rest were open circuit.

Meaning, you guys could have said that R2 (or R1 or R3) was shorted, and the rest i, e R1, R3, and R4 were open.

Paullace said:   8 years ago
I think that is no so complex, in this case, it doesn't matter if the G is conductance or galvanometer.

If the short circuit wasn't in R4 , is so simple as the ammeter that is connected between R3 and R4 should display 0.0000A instead of 2.4A. So R4 should be shorted.

Vishu gupta said:   8 years ago
@Shivanand.

You solved the question simply with the IQ. Thanks brother.

Ravi said:   6 years ago
You explained well, thanks @Pankaj.