What will be the total resistance of ideal voltage source?

In summary, the conversation discusses the concept of total resistance in a circuit with an ideal voltage source and a single resistor. It is clarified that an ideal voltage source has zero internal resistance and can power any load while maintaining a constant voltage. The concept of equivalent impedance is also mentioned, with two different circuits for DC and AC analysis. The need for a well-stated question is emphasized, with a clarification on the definition of "total resistance" and the need to specify the points between which it is measured.
  • #1
Sampad Saha
15
0
If we connect a single resistor in the circuit of ideal voltage source then what'll be its total resistance? ? Isn't it zero? As shown in image .so is it possible that the total resistance of a circuit is 0 Although it has 5ohm resistor!?
IMG_20150403_091252.jpg
 
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  • #2
An ideal voltage source can power any load you throw at it while continuing to maintain a constant voltage. So its resistance remains zero.
 
  • #3
NascentOxygen said:
An ideal voltage source can power any load you throw at it while continuing to maintain a constant voltage. So its resistance remains zero.
yaa..Sir, I know that its internal resistance must be zero. But what's about total resistance of the circuit? Is it also be zero?
 
  • #4
If that wasn't the answer to your question, then you weren't asking the right question. The voltmeter is across the source, so regardless of what else is going on, its voltage is held fixed by that source.

The effective resistance of a circuit comprising an ideal voltage source in parallel with anything is zero ohms.
 
  • #5
Sampad Saha said:
yaa..Sir, I know that its internal resistance must be zero. But what's about total resistance of the circuit? Is it also be zero?
I think maybe you are confused about the calculating the equivalent impedance (resistance in your case) of a circuit.
There are 2 circuits to draw.
The first circuit is the Thevenin equivalent of the circuit. In your case, it would be an ideal voltage source with a 0 Ohm series resistance. This circuit is used to calculate DC values mostly. So in this case if the voltage is 5 V and the load resistor is 5 Ohms, the DC current is 1 Amp.
The second circuit is the equivalent impedance (or resistance in your case) of the circuit. This circuit is calculated by replacing ideal voltage sources with a wire (I.e., shorted). In your case, this circuit becomes just a resistor of 0 Ohms (Note that there is no voltage source in this circuit). The 5 Ohm load is still across the terminals. Normally this circuit is used for AC analysis. Suppose you connect a 110 VAC supply with a 110 Ohm resistor in series across the 5 Ohm resistor. What is the AC voltage across the 5 Ohm resistor? By superposition, the voltage across the terminals is 5 Volts DC (calculated from the first circuit) plus 0 VAC (calculated from the second circuit). Normally the equivalent impedance is not zero and there is an AC component across the terminals. By using the equivalent circuit impedance, the task of calculating signal levels is made easier.
Hope this helps.
 
  • #6
Sampad Saha said:
If we connect a single resistor in the circuit of ideal voltage source then what'll be its total resistance

A question well stated is half answered.
Above question is not well stated. You introduced a term that you did not first define.

Just what do you mean by "total resistance" ?
The "total" of all the resistances in your circuit is 5 ohms + Rvoltmeter.

Are you considering your voltage source and resistor as being in series or being in parallel when you measure "total resistance" ??

You must define between what two points you intend to measure said "total resistance" .
 

1. What is an ideal voltage source?

An ideal voltage source is a theoretical concept used in circuit analysis. It is a voltage source that maintains a constant output voltage regardless of the current drawn from it.

2. What is resistance?

Resistance is a measure of the opposition to the flow of electric current in a circuit. It is represented by the symbol "R" and is measured in ohms (Ω).

3. Can an ideal voltage source have infinite resistance?

No, an ideal voltage source has zero internal resistance. This means that it can provide an infinite amount of current without changing its output voltage.

4. How does an ideal voltage source impact total resistance in a circuit?

In an ideal voltage source circuit, the total resistance is solely determined by the components connected in the circuit. The ideal voltage source itself does not contribute to the total resistance.

5. How do I calculate the total resistance of a circuit with an ideal voltage source?

To calculate the total resistance in a circuit with an ideal voltage source, you need to add up the resistances of all the components in the circuit. The ideal voltage source itself can be ignored in the calculation.

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