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
resistortwo 220 resistors
resistorsthree 220 resistors
resistorsfour 220 resistors
resistorsDiscussion:
44 comments Page 3 of 5.
Rajesh said:
1 decade ago
For a single resistor voltage drop is maximum across that resistor, so power is maximum. But when two or more resistor come into picture then voltage drop across the resistance will be lesser than previous one so power will be less.
Ramesh said:
1 decade ago
Can any one explain? What happens if parallel combination is there?
Sriksnth said:
1 decade ago
P = v^2/r.
Power is inversely proportionally to resistance. So, as resistance is less power will be more.
Option A is correct.
Power is inversely proportionally to resistance. So, as resistance is less power will be more.
Option A is correct.
Rupesh said:
1 decade ago
What about maximum power transfer theorem? Which says the max power will be transferred to the load when load impedance is equal to the source impedance. It means if load independence is greater than the source impedance then the power transferred to the load is less and vice versa. If we match both the incidences we can get max power and max heat dissipation. So the question is what is the value of source impedance of 120 volt source?
Sahi said:
1 decade ago
Higher the resistance lower the power dessipation.
Ponjothirajalingam said:
1 decade ago
But at the same time Power is directly proportional to resistance only.
Dilip said:
1 decade ago
Power = v*2/r.
If r is minimum then power has maximum value.
And we know that i = v/r.
And p = i^2*r directionally proportional.
If r is minimum then power has maximum value.
And we know that i = v/r.
And p = i^2*r directionally proportional.
VARA PRASAD said:
1 decade ago
Power consumption formula is V^2/R.
Here V is constant so whenever R value is low V^2/R value is more.
So R value is low at single 220 ohms resistor.
Here V is constant so whenever R value is low V^2/R value is more.
So R value is low at single 220 ohms resistor.
Krish said:
1 decade ago
Resistor is a device which resists the flow of power through it, The answer will be chosen from the least value of the options simple.
Binay said:
1 decade ago
As p = v^2/r, here v constant, So pr = constant.
So for max p, r should minimum.
So for max p, r should minimum.
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