ELECTROMOTIVE MAGNETIC FORCE emf measured as volts . It does not guarantees a current or power but just the force is present. With a load it may disappear
Because emf is the very source of voltage, either chemical or inductive, an can be meassured at open circuit only so, internal resistance of the supplier is not affecting it.
to find the relation between emf generated and Field current .....
A voltmeter is used to measure voltage. A potentiometer is used to vary the amount of resistance in a circuit - it has nothing to do with measuring.
A magnetic field will not generate an EMF if there is no motion, so the primary factor causing a permanent magnet generator to not generate EMF is if it is not turning.
Well, you should really measure the open-circuit voltage and the short circuit current both under dark and light conditions and then compare them to fully characterize a solar cell. Measuring the open-circuit voltage means measuring the voltage across the cell when no current is flowing (i.e., with a LARGE resistance as a load on the cell). Measuring the short-circuit current means measuring the current when the voltage across the circuit is essentially zero (i.e., with a VERY SMALL resistance as a load on the cell--thus, "short-circuit" current).
The electromotive force (emf) of a cell measured by a potentiometer is accurate because a potentiometer measures the potential difference between the two electrodes without drawing any current from the cell, leading to minimal disturbance in the cell's internal resistance. This allows for a more precise measurement of the emf of the cell under open circuit conditions.
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.
With cells connected in series, the total emf of the 'stack' is simply the sum of the individual emf's of the individual cells. -- Even if one cell is connected backwards in the string. Then its emf is considered negative when the sum is being performed. -- All of this is true only as long as there is no external connection between the ends of the stack, you're measuring the emf on an 'open-circuit' basis with a voltmeter, and the cells are not providing any current to an external circuit. Once the series combination of cells is connected to an external circuit and begins to produce current, the total emf at the terminals of the stack will decrease. It'll depend on the magnitude of the current, and on the 'internal impedance' of each cell. If the cells are not precisely identical and in identical states of charge, then a calculation of the total emf is virtually impossible.
Because emf is the very source of voltage, either chemical or inductive, an can be meassured at open circuit only so, internal resistance of the supplier is not affecting it.
Bcoz the emf which is to be measured is less than emf of driving cell....
to find the relation between emf generated and Field current .....
You can measure the emf of a cell by using a voltmeter, as this draws current from a cell. You can use the voltage, the emf, and the load resistance to determine the internal resistance of the cell.
No. But if you increased the EMF across the circuit, then more electrons would flow through it each second.
To measure the electromotive force (EMF) of a cell accurately, use a voltmeter with high precision and connect it to the terminals of the cell. Ensure the cell is not connected to any external circuit during the measurement to prevent errors. Take multiple readings and calculate the average to minimize inaccuracies.
The induced emf in a circuit is not directly dependent on the resistance of the circuit. It is primarily determined by the rate of change of magnetic flux through the circuit. However, the resistance of the circuit can affect the current flow and ultimately impact the magnitude of the induced emf through Ohm's law (V = IR).
A voltmeter measures potential difference across a component, which may not necessarily be equal to the EMF of a cell due to internal resistance in the cell and voltage drops across other components in the circuit. To accurately measure the EMF of a cell, a potentiometer or a high-resistance voltmeter is used in conjunction with a null point method.
It suggests that :- An EMF is set Up in circuit when the magnetic flux linking the circuit is changed in any manner.The magnitude of this EMF is proportional to the time rate of flux linkage with circuit.