Electrical Engineering - Series-Parallel Circuits - Discussion

Discussion :: Series-Parallel Circuits - General Questions (Q.No.5)

5. 

A voltage divider consists of two 68 k resistors and a 24 V source. The unknown output voltage is

[A]. 12 V
[B]. 24 V
[C]. 0 V
[D]. 6 V

Answer: Option A

Explanation:

No answer description available for this question.

Gopinath said: (Dec 13, 2010)  
Give explaination.

Nafish said: (Mar 2, 2011)  
24V is divided into two part each= 24/2 = 12V

Bhavani said: (Mar 24, 2011)  
I want explanation for this.

Thanks. !

Isocuraphil said: (Apr 22, 2011)  
Ok how come it is 12?

Sushma said: (Jul 17, 2011)  
Vout=(R2/(R1+R2))Vin for a voltage divider,when a input voltage is applied across a series of resistors R1&R2 and ouput is the voltage applied across R2.
here,Vin=24V,R1=R2=68ohms,
so,Vout=(68/(68+68))24
=12V

Ganeshbabu said: (Jul 25, 2011)  
Thanks sushma.

Anand said: (Jul 27, 2011)  
Nice Explanation Sushma...

Santhosh said: (Sep 6, 2011)  
Thank you sushma.

Bala said: (Sep 11, 2011)  
Thanks sushma.

Pradeep said: (Sep 17, 2011)  
Thanks Sushma.

Sri said: (Sep 18, 2011)  
V2=V1R1(R1+R2) and putting the values we get 12

Sagata said: (Nov 12, 2011)  
We know voltage in one of the 68 ohm resistor is V=I.R1(R1=resistance of one of the resistors )
again V=(V/R).R1(R=total resistance of circuit.)

Hence,V=[24/(68+68)]*68=12V

Voltage divider rule is applicable for series circuit only because in series only voltage varies but not in paralel circuits.

Pratik Shah said: (Jan 7, 2012)  
Thanks sagata.

Mr. Kathiravan From Vellore said: (May 19, 2012)  
Voltage Divider (Vout)=(R2/(R1+R2))xVin

= (68/(68+68))x24

= 12V

Arundeep Singh said: (Jun 22, 2012)  
Voltage divider always in series combination so solve it by voltage divider method as 24 V/ 2 = 12 we as both are having equal value so voltage will be divide and current will remain same.

Jadecliff said: (Jul 28, 2013)  
From my opinion,

In series, total voltage is the sum of individual voltages.

V1 is the voltage output after the current I which is the same in series passes through the resistor R1(68).

R(total) = 68+68 = 2 x 68.

We know total voltage supplied is 24.

V(total) = I * R(total).

I = 24 x 1/(2x68) = 12/68.

I = I1 = I2.

So V2 = I x R2 (V2 = output voltage after passing R2).

= 12/68 x 68.

= 12 V.

Subhojit said: (Aug 25, 2013)  
A voltage divider consists of two 68 k resistors and a 24 V source.

The unknown output voltage is:

In this question there is no specification that the Vout is across which resistor that is whether it is across r1: 68 ohm or r2: 68 ohm or across r1+r2 : 136 ohm. So answer may be 12v or 24v. Data insufficient.

K Vamsi said: (Aug 27, 2013)  
Hello @Subhojit,

In this question these 2 resistors are in series and same value so voltage across any of the resistor is same I think if it is wrong tell me with clarity.

Sakthi said: (Sep 6, 2013)  
In voltage divider the resistors will be in series. So to find the voltage across any resistor just apply the voltage divider rule. Another way is, find the total resistance and the current, then by using OHM's law we can easily find the voltage across each resistor.

Circuit Breaker said: (Jan 6, 2014)  
Unknown out put voltage = (24*68)/(68+68).

= 12v.

S.C.Mathur said: (Mar 9, 2014)  
The output voltage changes with load resistance and it has not been given that the circuit is a closed circuit, so the output voltage will be 24 volts until and unless load is connected at output, Also voltage will not vary until and unless there is a flow current in the circuit. The calculations done in above explanation have been considered in parallel which is not correct. Even if voltmeter is connected across output the internal resistance of the volt meter will be in parallel with the two resistances of voltage divider.

Narender said: (Mar 1, 2015)  
1st draw the circuit diagram of the question then you will get the answer simply by observing the circuit diagram.

Dasu Namburi said: (Apr 14, 2015)  
It is totally wrong because output voltage means consumed voltage except source so answer is 24.

Dasu Namburi said: (Apr 14, 2015)  
He is not specifying individual divider o/p voltage. He ask only o/p voltage means 24v(consumed at series resistors).

Arun said: (Jun 4, 2015)  
Where we need to calculate output?

Augustin said: (Jan 9, 2016)  
How can solve answers is 12 V brief explain.

Shobitha K N said: (Feb 20, 2016)  
Voltage divider general formula:

Vout = (Z2/(Z1+Z2))*Vin.

Vout = (68/136)*24.

Vout = (1/2)*24.

Vout = 12.

Karthik Holla said: (Mar 19, 2016)  
In voltage divider circuit if the resistance are same then output will be half of input voltage.

Prawin said: (Sep 19, 2016)  
Thanks @Sushma.

Preethi said: (Oct 8, 2016)  
Nice @Sushma.

Abrha said: (Nov 24, 2016)  
Thanks for your clear explanation @Sushma.

Rithu said: (Feb 21, 2017)  
Please explain me to understand it.

Vidhya Sri said: (Mar 1, 2017)  
Clear explanation, Thanks @Sushma.

Abhishek said: (Aug 19, 2017)  
Resistance in kilo ohm and answer in volt.

Ameesh Devwrat said: (Aug 28, 2017)  
In a voltage divider circuit there are always 2 resistors in series say r1 nd r2.

The output is taken across say r2.

Then the output voltage will be;

Vo=(r2/r2+r1)vi.
Vi is input voltage.
Therefore;
Vo=(68/68+68)24=24/2=12.

Viswa said: (Sep 1, 2017)  
Great answer @Sushma.

Amresh said: (Sep 21, 2017)  
Unkown output voltage means voltage drop across the last element. Here bothresistance value is same so 12v is coming.

Nani said: (Apr 16, 2019)  
@All.

Hi, Here it is mentioned as a voltage divider. That means, its a simple series circuit across one voltage source.

Unless otherwise mentioning the output terminals, we cannot assume that the unknown voltage is across one of the resistance or so.

I think input data in the question has to be elaborated. Correct me, if I am wrong.

Sadik said: (Aug 28, 2019)  
Thanks @Sushma.

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