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emf and voltage
AnswerElectromotive force is the potential difference created by a source, such as a battery or generator, when it is not connected to a load -in other words, on 'open circuit'.
Voltage drop is the potential difference across a load, such as a resistor, which causes current to flow through that load.
A voltage drop occurs, internally, in batteries and generators, when they are supplying a load. The battery or generator's terminal voltage, when supplying a load, is its e.m.f. less its internal voltage drop.
What else can I help you with?
Why the output voltage drop when the load current is increase?
As the load current increases the losses in the circuit increases (I2R loss) and speed of the generator decreases so the voltage falls a little. and this voltage fall can be adjusted by increasing the speed of the generator and Iron losses are taken as constant losses.
What is the emf induced at zero field current.and what does it signify?
EMF is the voltage across a coil (or motor) due to changes in the magnetic field. If you change the current the coil will generate a voltage (in the opposite direction of the current). So it is not the field but the change that matters.
What happens to the generated voltage of a self excited generator if shunt field resistance is greater than the critical resistance?
it doesn't develop emf ..........
If A generator has an armature resistance of 0.6 ohms and when connected to a load of 40.9 ohms passes a current of 3.5 A what is the terminal voltage and generated EMF?
145.25 v
Which increases or decreases the voltage of alternating current?
(i) EMF (Electro Motive Force) the source of voltage can increase or decrease voltage. (ii) Load connected can increase or decrease voltage (In case of overload voltage reduces.) (iii) Resistance of wire - I R loss ( Voltage drop V = IR)
How does voltage drop related to impressed emf?
Voltage drop is resultant of IR ie current and the line resistance, not dependent on impressed emf
What is the potential difference between two points in a circuit is called?
Voltage drop
Why do you measure emf with a potentiometer not with voltmeter?
EMF (E''electromotive Force'') is another term for Volts, hence the E in electronic formulas and EMF is measured with a volt meter. A potentiometer is not a meter at all, it is a variable resistor
What are the differences between potential difference and emf?
Potential difference is the difference in electric potential energy between two points in a circuit, while electromotive force (emf) is the total energy provided per unit charge by a battery or voltage source. In other words, potential difference measures the voltage drop across a component in a circuit, while emf represents the energy per unit charge supplied by the source.
What is the Condition for terminal voltage across a secondary cell to be equal to its emf?
The condition for the terminal voltage across a secondary cell to be equal to its emf is when there is no current flowing through the cell. When there is no current, there is no voltage drop across the internal resistance of the cell, and thus the terminal voltage equals the emf.
It can be said that pressure and electromative force are the same?
There is analogy between pressure and EMF or voltage. What pressure is to the liquids, EMF or voltage is to electric current. But, of course, they are not the same.
Difference between back EMF and induced EMF?
An induced electromotive force (emf) is an induced voltage. Voltage (emf) causes current flow, and this induced voltage will cause a current that is called the induced current.We might also add that the induced current will cause a magnetic field to expand about the current path, and this field will "sweep" the conductor. The sweeping of the conductor by that expanding magnetic field will set up an emf that will oppose the emf that was creating it.CommentTechnically, there is no such thing as an 'induced current'. It is voltage that is induced. Any current flows as a result of that induced voltage being applied to a load. But that current is certainly NOT induced!
Can terminal potential difference be greater than the emf supplied?
No, the terminal potential difference cannot be greater than the emf supplied. The emf represents the maximum potential difference that the cell or battery can provide, while the terminal potential difference is the actual potential difference across the terminals when a load is connected.
A device that provides an emf?
EMF (short for "electromotive force" - not a well-chosen name, since it isn't exactly a force) is more properly called a "voltage". A device that provides that can be a battery, or you can get the voltage from the outlets in your home.
Can the terminal voltage of a battery be larger than its emf?
the voltage of a battery could be larger than the emf if you are to charge the battery, in that case V=E+Ir .
Is emf current greater than current?
EMF is electromotive force. It is another name for voltage. Voltage is electric potential in joules per coulomb. Current is electric flow, in amperes. Amperes are coulombs per second. Voltage and current are not the same thing, and "emf current", or "voltage current" does not make sense.
Another name for EMF?
"Potential difference" or "Voltage".
