Current and voltage source

[reachrkata]

You got it wrong, in fact the opposite.
A battery is indeed a voltage source. Assuming it is well charged, it maintains the same voltage irrespective of the load.

Regarding a current source, I would say it is usually used as tool for circuit analysis. Though we can build circuits that act as a constant current source, we don't have a device (like a battery) that is a current source.

-Karthik

[Aoedogg]

Originally Posted by Eddy boy

Is a battery is a voltage source? if yes then how ? it does not maintain voltage across its terminals when load resistance is altered...please give example of voltage source if any?

In general we would assume an ideal source, this means that it would be able to maintain a constant voltage/current regardless of the load.

In reality because of internal resistances, this is not possible. Generally in circuit analysis you would assume an ideal source, you should be aware of the deviation however.

To answer your question, assuming an ideal source, a battery would generally be considered a voltage source.

[Eddy boy]

ok thanks.

[sauravgoswami]

but buddy batteries are measured in Ampere/hour,so why they take current into consideratiuon when it is a voltage source???

[Eddy boy]

Explain your question sauravgoswami.Current and voltage relation is like mother and son,you can never separate one from other.

[Eddy boy]

frnds are you agree ,batteries are voltage source??i will never agree let me explain you in circuit loading if the load resistance is less than battery internal resistance then how you prove batteries are voltage source.

[hassan.buet07]

yes, battery is a ideal voltage source. But it is not an ideal voltage source. It has some internal resistance in series with the load resistance. Therefore a little voltage drop occurs across the internal resistance. hence with the alternation of load resistance voltage across the load also changes.

[Fahad Bhatti]

battery is a voltage source and ideally it must maintain the voltage across it, but practically it is not seen in poor batteries as they attenuate their voltage level when used extensively, this actually happens due to charge deposit on electrodes of the battery with time... thus if no deposit occurs in batteries (i.e. an ideal condition) , then batteries will not lose their voltage even if resistance is varied
Another good example of voltage source is Synchronous Generator, it does not vary its voltage with load but may vary the supply frequency