Electrical Engineering - Series Circuits - Discussion

Discussion Forum : Series Circuits - General Questions (Q.No. 5)
5.
Which of the following series combinations dissipates the most power when connected across a 120 V source?
one 220 resistor
two 220 resistors
three 220 resistors
four 220 resistors
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
44 comments Page 4 of 5.

Raviraj said:   1 decade ago
@Hemraj.

For P=V^2/R

In this case the resistance and power are having inverse relation, so by this we can conclude that as resistance is less power dissipation will be more.

And for P=I^2.R here the resistance and power are having direct relation, So more resistance causes of more power dissipation.

But as we know current through the CKT depends on Voltage, so we can take voltage as constant so as per P=V^2/R the resistance is less power dissipation will be more.

Ashu said:   1 decade ago
As we know current passes maximum through minimum resistive path. So as per the formula of power P=I^2*R.

Square of I decreases with increase in resistance. So minimum the resistance maximum the power.

Amarender said:   1 decade ago
In the series if we increase resistance one by one current will be lower than previous. Hence we know the P=V*I.

Or in other words if we increase the resistance power dissipation will be low according to V^2/R.

Satishgnd said:   1 decade ago
Very good explanation Harpreet.

Mohit said:   1 decade ago
If you know that in domestic wiring we have parallel connection to minimize power dissipation.

If we do in series then voltage will be low and power dissipation will be high.

Think about it.

Himanish said:   1 decade ago
YES I am also having the same confusion....
P=VI
V=IR
So P = (I^2)R

BUT again P = (V^2)/R
These statements are contradictory but both are true...

Sadik pasha said:   1 decade ago
In series, number of resistors increase total resistance increase so resistance increase current decrease so power dessipation less.

Hemraj said:   1 decade ago
In this case

P=i^2*r power dissipation is perportional to the ressitace. So more resistace causes of more power dissipation.

Balaji said:   1 decade ago
Nice explanation by lavanya.

Shikha said:   1 decade ago
Very good explanation Harpreet.


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