Electrical Engineering - Parallel Circuits - Discussion

Discussion Forum : Parallel Circuits - General Questions (Q.No. 25)
25.
In a five-branch parallel circuit, there are 12 mA of current in each branch. If one of the branches opens, the current in each of the other four branches is
48 mA
12 mA
0 A
3 mA
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
22 comments Page 1 of 3.

Saurabh K. Chhaya said:   1 decade ago
In parallel branch circuit voltage remains same and current are differents in each branch

So 12*5= 60 and 12*4=48 so ans is 'A'

Amit Chakraborty said:   1 decade ago
For five parallel branch total current is 60mA
If one branch is open then the total current become 60-12=48mA
So current in other branch 48/4=12mA

Boobash said:   1 decade ago
@Amit is correct because the question is each other four branch.

Sweta said:   1 decade ago
In parallel branch circuit, there is equal voltage drop in each branch. Since equal current flows in each branch. Hence there is equal resistance present in each branch.

I1*R1 = I2*R2.
60*(R/5) = I2*(R/4).
I2 = 48.

Current in each branch will be 48/4 = 12.

Karthik said:   1 decade ago
This is tricky q, they are asking what is the current in other 4 branch if the resistance is opened.

So as per above the answer is 12 but logically its 15 in each branch.

(ie) 12 + (12/4) = 12 + 3 = 15.

Ashwath said:   1 decade ago
Total current in this circuit must be = 12+12+12+12+12 = 60 mA.

So, if we remove one branch then total current must be same.

Therefore answer must be = 60/4 =15 mA.

Vishal Bastal said:   1 decade ago
I agree with @Ashwath.

If voltage remains same means then there will be same current in circuit.

If one branch is removed means total current is distributed among four resistors.

So 60ma/4 = 15ma.

Priyvrat said:   9 years ago
When the circuit gets opened, no current flows. So I suppose 0.

Prashant Kumar said:   9 years ago
You are assuming a constant current source and no load on each branch. In that case yes your answer would be right.

However, consider this:

The current through any one resistor (or branch of the circuit) will be I = V/R = 10/1000 = 0.01I = V/R = 10/1000 = 0.01.

The total current drawn from the power supply will, of course, be 4x that since there are 4 branches, all at 10mA.

Now, remove one branch, and what happens?
Each branch still has I = V/R = 10/1000 = 0.01, since that hasn't changed at all.
What has changed though is the total current?

Since there are now only 3 branches the total current drops to 30mA, as that is 3 x 0.01.
The only ways the current through any branch could change is if a) the resistance in that one branch changes, or b) the voltage of the power source changes.

Prashant jayant said:   9 years ago
Here, it is asked each of the other branch neither four branches. So, the correct answer is 12mA.


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