Electronics - Parallel Circuits - Discussion

1. 

When parallel resistors are of three different values, which has the greatest power loss?

[A]. The smallest resistance
[B]. The largest resistance
[C]. They have the same power loss.
[D]. Voltage and resistance values are needed.

Answer: Option A

Explanation:

No answer description available for this question.

Seshendra said: (Nov 10, 2010)  
p=vi,
v=ir,
i=v/r,
so
p= v2/r

In problem the resistors are in parallel. The voltage across parellell resistors are same. So V is constant.
Now Power is inversely proportional to resistance. Less resistance value resistor have the gretest power loss....

Sravanthi said: (Feb 14, 2011)  
Obviously more current flows through less resistance. Power= (i^2) R.

Rupa Khilare said: (Feb 22, 2011)  
Higher the value of resistor, lesser the value of current, and as value of current is less then greatest the power loss.
As, p=vi
=2v/r.

Vigneshwaran said: (Mar 7, 2011)  
i=v/r if value of r is small,i will be more..........

p=i^2r therefore the loss will be more

Saichaitanya said: (Apr 2, 2011)  
WHY NOT THE CORRECT ANSWER IS OPTION D??????

SINCE, P=VI, V=IR

THEREFORE, P=(IR)*I => P=(I^2)R

Khan said: (Apr 19, 2011)  
In the equation P=(I^2)R ...........I is not constant so we cant consider it.

Hence P=V2/R is correct as in this case V is constant as parallel resistance has same voltage.

However if it would have been series circuit then your answer will be right.

Neha Paunikar said: (May 19, 2011)  
Since power is inversely proportional to current I.

Deepak Aneja said: (Jun 13, 2011)  
When three resistances are connected parallel with same battery(cell)of voltage v . current divides & flows through parallel combination of resistances. max. current flows though the resistor of smaller value

as p=vi here i is large for smaller value of resistor.

Mahtaj Banu said: (Oct 22, 2011)  
As p=v*i.

And v=i*r.

So on substituting we in p, we get p=i*i/r.

Which implies p and are are inversely proportional. So for high power it is low resistor and vice-versa.

Bruno said: (Mar 28, 2012)  
In simple Short circuit haven't any load(That mean havn't parallel
Resistors )(In short circuit power loss is occur).So small resistance is almost like to short circuit..AS A RESULT SMALL RESISTANCE IS FOR HIGH POWER LOSS.

Ravikumar said: (May 20, 2012)  
Considering the ohms law p=v^2/R so, if are is low power loss is more.

Bhawna said: (Aug 18, 2012)  
The resistors are in parallel & in parallel voltage is same but in parallel current divides, current follows the low resistive path, so high pwr loss occurs in small resistance.

Catcracker said: (Sep 5, 2012)  
In parallel voltage constant dats by we take p=v^2/r...if we take p=i^28r...p may vary with variation of "i" bt in p=v^2/r.....p varies with variation of r.

Lakshmi said: (Oct 4, 2012)  
As the resistors are connected in parallel, the voltages are same. According to P=V^2/R smaller the resistance greater the power loss.

P Vinoth said: (Oct 26, 2012)  
The total source voltage equal to the voltage across elements, according to this V=IR (voltage drop depends on current and resistance value only). The current flow value depends on voltage source are connected to that circuits and resistance value, so that power loss mainly depends on the resistance and voltage value only. Due to this P=VI=V2/R (power in inversely proportional to the resistance). The maximum power loss will occur if low resistance value.

Siddhartha said: (Mar 17, 2013)  
Since the tendency of current is to chose least resistance path and p=i^2r then the current inside lowest resistance will higher so the power is also higher.

Lakshmi said: (May 20, 2013)  
What is the difference between power loss and power?

Imran Ullah Khan said: (Sep 1, 2013)  
More current will pass through the lowest resistor and we know that p = i^2*r.

Mangaiyarkkarasi said: (Mar 26, 2014)  
Power is inversely proportional to resistance. So less value of resistance has great power loss.

Nouman Khaliq said: (Jul 4, 2014)  
Please explain power and what's the difference between power and voltage here ?

Pramod Bisht said: (Aug 19, 2014)  
The greatest resistance has the highest power loss.
Because Voltage will be same for all resistance.

And the highest current flow from the lowest value of resistance,
Because I = V/R.
So now P = VI.

So the lowest value resistance has the max. power and so on power loss will be minimum.

So option B is right.

Azhagusurya said: (Feb 20, 2015)  
p = vi-----1.

i = v/R----2.

Sub 2 in 1.

p = v(v/R) = v^2/R.

So when resistance decreases power loss increases.

Gayathri said: (Nov 21, 2015)  
I do agree with option A since p = v2/R.

Siddharthachaitanya said: (Jan 7, 2016)  
Current always choose low resistance path. So the current flow through the resister is high. And the voltage across all resisters is equal when they connected in parallel know apply p=vi.

So here i is high when its having small resistance value so therefore p also high through the resister which is having smaller value.

Yalam Vyshnavi said: (Feb 10, 2016)  
Please tell me the difference between power & power loss for a resistor. Why we have to think that there is a power loss in the resistor, what about power gain?

Kyle Radz said: (Jan 4, 2017)  
According to ohm's, the greater, the resistance, the least power loss and vice versa.

Rajashekhar said: (Aug 9, 2017)  
If voltage across in parallel resistor is same so current flow is depends on the value of restistance of resistor.

High resistor have low current flow & power loss also low.

Shadan said: (Feb 6, 2018)  
Let,

R1= 2ohm.
R2= 4ohm.
R3=6ohm and Vs=12 V.
and according to the question all the resistors connected in parallel.
P1=V^2/R1 =12*12/2 = 72 W.
P2 = V^2/R2 = 12*12/4 =36 W.
P3 = V^2/R3 = 12*12/6 = 24 W.

Now, you can see small resistance have greater power loss than other
Note:- All the values are an assumption you can check by posting of different values or different methods to remember.

Hani said: (Mar 18, 2019)  
Great, Thanks @Shadan.

Gautham said: (Mar 23, 2019)  
@All.

As the question referred to the greatest power loss in which resistance, not the greatest power consumed.

Let put in a nutshell power loss proportional to resistor value, consider resistor as a load and load drop occurs in the resistor and at the same time loss component is there in resistor which is exhibited in terms of heat. If resistor value is high heat will be high and of course, loss is high.

Jadav said: (Apr 24, 2019)  
Because W=I*I*R.

So small resistance have high current and power is square of the current.
So, Ans is the smallest resistance.

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