The emf of a batter as it is used will stay the same.
A battery clip is used to connect a battery securely to a device or circuit by attaching to the battery terminals. It provides a convenient way to make and break the connection between the battery and the device without needing to solder the wires directly to the battery terminals.
it is because earlier it was thought to be a force inside a battery that takes the electrons from lower potential terminal to higher one in a mysterious way and hence a force . But , now we know that emf is the external work expended per unit of charge to produce an electric potential difference across two open-circuited terminals . And the electrons do so due to the electric field inside the battery..
It's primary usage is to determine the nature of an induced EMF from changes in the magnetic flux through a circuit. However, you must use Faraday's Law (and a unit conversion factor) to determine the SIZE of such an EMF.
What is the range of the EMF spectrum
If the EMF or voltage source is removed from a conductor, the electron flow will eventually stop. This is because the EMF or voltage source provides the force that drives the movement of electrons through the conductor. Without this force, the electrons will no longer be pushed and will come to a rest.
the voltage of a battery could be larger than the emf if you are to charge the battery, in that case V=E+Ir .
Bcoz the emf which is to be measured is less than emf of driving cell....
EMF, or electromotive force, is a measure of the energy provided by a source (such as a battery) to move a unit charge around a closed circuit. It is responsible for driving the flow of electric current in a circuit. EMF is measured in volts.
"The potential difference between the terminals of a battery will equal the emf of the battery when there is no current in the battery. At this time, the current though, and hence the potential drop across the internal resistance is zero. This only happens when there is no load placed on the battery-that includes measuring the potential difference with a voltmeter! The terminal voltage will exceed the emf of the battery when current is driven backward through the battery, in at its positive terminal and out at its negative terminal." Raheel Ahmed Quaid i Azam University Islamabd Physics Dept
The amount of "push" provided by a battery is its electromotive force (emf). In common alkaline batteries, the emf is 1.5 volts.
The EMF of a battery made up of cells in series is equal to the sum of the EMFs of the individual cells. When cells are connected in series, their voltages add up. For example, if you have two 1.5V cells in series, the total EMF of the battery would be 3V.
To measure the total emf simply connect the battery and voltmeter with the right terminals , but to measure the terminal potential difference which is less than the emf the voltmeter is connected in parallel with the battery
E. Joined in parallel, the voltage (or electromotive force, "emf") isn't additive. You'd get four times the current, or four times the life of a single battery, but it would have the same voltage.
If the emf of a battery is E Volt, the potential difference across a battery is given byV = E -I r where I is the current in the circuit and r is the inetrnal resistance.Hence E and V will be equal only when I = 0.The maximum potential difference across the battery will be equal to E only if I = 0.In gnereral potential difference can be equal or less than the emf.E.m.f can never exceed the potential difference.=====================================A battery charger is a device used to put energy into a secondary cell or (rechargeable) batteryby forcing an electric current through it.Hence to charge a battery another source of emf is needed.The combined emf is now will be (E - E1) where E is the emf of the battey in quesiton and E 1 is the emf of the external source used to charge the battery.Note that E-E1 will be negative in sign.======================================...A battery is charged only when its emf is less than its maximum emf.Suppose that the maximum emf of a cell is 1.5V. The battery should be charged only when its emf is less than 1.5 V say 0.5 V.To charge the cell we use a different source of emf E1 say 3V.The positive of the second source is connected to the negative of the cell so that theCombined emf is now 0.5 - 3 = -2.5V.The negative sign indicates that the emf is opposite to the emf of the cell which is 0.5V.Since the cell is getting charged, the difference in emf is gradually reduced to zero when the cell is fully charged.In modern charging units there are provisions so that the cell is never allowed to be over charged, even if the charging unit is in on for about 12 hours.When the cell is fully charged, (that is when the emf of the cell is now 1.5V), the potential difference between either the second source or cell will be zero.Taking into consideration the sign of the emf and the direction of current through the cell and the sign of the potential difference, the potential difference will be always less than the emf of the cell (which gradually increases while charging).Note that the potential difference is negative if the emf of the cell is taken as positive.Also note that the cell is charged only when its emf is less than its maximum e.m.f
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.
When it is being loaded.
The null method is used in measuring the unknown EMF of batteries. The method is about using a potentiometer circuit with the battery of a known and then an unknown EMF connected to it one after the other and locating, in each case, the position of the 'null point'; the point on the potentiometer circuit where the current through the battery is zero.