Electrical Engineering - Series-Parallel Circuits - Discussion

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.

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.

@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.

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.

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.

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.

I think here applying voltage division rules this used only for resistors connected with voltage source if not then the converted number of resisters is only 2 resistor formate so,

If you find.

R0 =Vi* (R1/R1+R2).
R0=24* (68/68+68) =12.

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.

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

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.