both emf and voltage are same? if its not so explain the concept clearly..
I think he describes motional EMF as voltages which are generated by changing fields vs voltage drops from energy loss in resistors.How does that show a difference between the terms "electromotive force" and "voltage"? Even Lewin used the terms interchangeably. His entire demo could have been done using one or the other term exclusively (flip a coin to pick which). His demo delves into the difference between conservative and non-conservative electric fields.
Ohm's Law is more commonly written as V=IR, but E=IR is still widely used. Just as P=IV and P=IE are both used.the e in ohms law is electromotive force, or voltage. there is no difference between emf and voltage, if there were, then ohms law would have to have different formulas. by the way, the I in ohms law is current in amps, just an older term for current.
Yes he would as that's the proper term for historic reasons to use.But he also used the term EMF for the battery, saying explicitly, "The battery has an EMF of 1V." (25 seconds into the Part 1 video).
Electromotive force, also called emf (denotedand measured in volt),[1] is the voltage developed by any source of electrical energy such as a battery or dynamo. It is generally defined as the electrical potential for a source in a circuit.[2]A device that supplies electrical energy is called a seat of electromotive force or emf. Emfs convert chemical, mechanical, and other forms of energy into electrical energy.[3] The product of such a device is also know as emf.
It's more a matter of the origin of that voltage not semantics and why when we measure circuits with a voltmeter we can get results that seem counter to the expected results if we think electricity is just a matter of current flow in a wire.So how is that different from what I posted in my first response, namely, "For most purposes, the terms are used interchangeably. I think a strict interpretation is that EMF is specifically the voltage produced by a source, whereas voltage is applicable to ANY potential difference."
I'm still not seeing any fundamental distinction. It is completely reasonable to talk about the output voltage of a source. While I would recommend against it, I would not say that it is wrong to talk about the EMF at the output of a voltage divider.
Add an adjective to voltage and you have a whole lot of terms including bias, de-ionizing, ionizing, etc.From Master Glossary, Module 20 of the Neets books:
ELECTROMOTIVE FORCE (emf) - The force (voltage) that produces an electric current in a circuit
VOLTAGE - (1) The term used to signify electrical pressure. Voltage is a force that causes current to flow through an electrical conductor.
- (2) The voltage of a circuit is the greatest effective difference of potential between any two conductors of the circuit
Why shouldn't we. If we want effective communications where the receiver understands the message, adherence to the definitions is a must. Otherwise, it's time to play 20 questions with the sender.It is not unreasonable to not worry about the definition and just get familiar with what we call the various voltages.
Good points but I would be careful on how you see kinetic energy moving into charge and lost energy from charge in a circuit....
Let's take the case of an EMF generated by a generator. If the generator is not hooked up to anything, then there are very few charges that are actually at a potential voltage corresponding to the EMF voltage. However, close the circuit, and the charges in the current are given the potential energy to do work (create kinetic energy in the charge for example, or heat up a resistor, as the charge loses energy)
I disagree. Assuming the generator is turning at the proper RPM, you can measure the potential difference between two points ... with a VOLTMETER. A battery not connected to anything, you can measure the potential difference between two points ... with a VOLTMETER. The voltmeter "completes" the circuit causing some current to flow, and given todays DVMs, we are talking little current.Let's take the case of an EMF generated by a generator. If the generator is not hooked up to anything, then there are very few charges that are actually at a potential voltage corresponding to the EMF voltage.
I dont mean that we should not try to define things as best we can. My point was that sometimes perfect definitions are not possible and we have working definition and general knowledge about which things fit into which classifications. I'm not sure EMF/Potential necessarily fits into this class, but there seems to be so much confusion about this question, even among knowledgeable people, that perhaps it is a factor in this case.Why shouldn't we. If we want effective communications where the receiver understands the message, adherence to the definitions is a must. Otherwise, it's time to play 20 questions with the sender.
Lol, you took my quote where I say "if the generator is not hooked up to anything" and then you hooked it up to a voltmeter.I disagree. Assuming the generator is turning at the proper RPM, you can measure the potential difference between two points ... with a VOLTMETER. A battery not connected to anything, you can measure the potential difference between two points ... with a VOLTMETER. The voltmeter "completes" the circuit causing some current to flow, and given todays DVMs, we are talking little current.
by Jake Hertz
by Duane Benson
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by Jake Hertz