Electrical Engineering - Energy and Power - Discussion
Discussion Forum : Energy and Power - General Questions (Q.No. 1)
1.
A 33 
half-watt resistor and a 330 half-watt resistor are connected across a 12 V source. Which one(s) will overheat?
half-watt resistor and a 330 half-watt resistor are connected across a 12 V source. Which one(s) will overheat?33
330
both resistors
neither resistor
Discussion:
58 comments Page 5 of 6.
Dayo said:
1 decade ago
Both resistors are connected in series, therefore same voltage flow across each of them & there s also balance in heat dissipated by each.
Suresh Maniar said:
1 decade ago
Both Resistances are Connected across same voltage of 12V.
Wattage=V square/R since V=Const or same for both smaller are value shall draw more power and heat up more.
Wattage=V square/R since V=Const or same for both smaller are value shall draw more power and heat up more.
Shekhar said:
1 decade ago
When the resistance of the conductor is more then current drop will be more then heat will generat more as compare to low resistance of the conductor.
Latha said:
1 decade ago
@Arti then how do you consider the wattage of resistance?
Biswajit said:
1 decade ago
What is half-watt resistor ?
Arti said:
1 decade ago
Heat generated = (square of current)* Resistance * time
This means higher the current, more is the heat generated.
For 33ohms resistance across 12 V source, current is 0.36A.Hence heat generated per second will equal to 4.28 joules.
For 330 ohms resistance across 12V source, current is 0.036A. So heat generated per second= 0.436 joules.
Hence Option A is correct.
This means higher the current, more is the heat generated.
For 33ohms resistance across 12 V source, current is 0.36A.Hence heat generated per second will equal to 4.28 joules.
For 330 ohms resistance across 12V source, current is 0.036A. So heat generated per second= 0.436 joules.
Hence Option A is correct.
Himanshu said:
1 decade ago
Option d is correct as both are taking same power and are connected in parallel (as given in question they are conected across 12 we supply. Across means parallel).
Jogi said:
1 decade ago
Actually depends on understanding that how both the resisters are connected. It is not clear how they are connected ie series or parell. It depends upon indually and its answer is different in both condition.
Gurbachan Dhiman said:
1 decade ago
Option D is correct because in // any type of load take current according its capacity ( Rating )
Anai relish said:
1 decade ago
Yeah its connected in parallel so we have different currents
so I(1)=v/r1=12/33=0.3636
P(1)=I^2*r1=4.3636>0.5W (so it gets heated up......)
I(2)=v/r2=12/330=o.o3636
P(1)=I^2*r2=0.43636<0.5W (so it is not heated.....)
Therefor the answer is op:A
If it is connected in series then we have
R=r1+r2=363
I=v/R=12/363=0.033
P1=I^2*r1=0.0359<0.5W (not heated....)
P2=I^2*r2=0.0359<0.5W (not heated....)
So answer is Option D is correct answer.
so I(1)=v/r1=12/33=0.3636
P(1)=I^2*r1=4.3636>0.5W (so it gets heated up......)
I(2)=v/r2=12/330=o.o3636
P(1)=I^2*r2=0.43636<0.5W (so it is not heated.....)
Therefor the answer is op:A
If it is connected in series then we have
R=r1+r2=363
I=v/R=12/363=0.033
P1=I^2*r1=0.0359<0.5W (not heated....)
P2=I^2*r2=0.0359<0.5W (not heated....)
So answer is Option D is correct answer.
(1)
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