What is the reason that terminal voltage is less than emf?

What is the reason that terminal voltage is less than emf?

The terminal voltage of the cell is less than its emf as the cell emf which is brought in the dielectric in the direction opposite to direction of external terminal voltage.

Can terminal voltage be less than emf?

4 Answers. Yes it can, for example when a cell is being recharged the terminal pd is V=E+IR where E is the emf of the cell, I is the current passing through the cell from positive to negative terminal and R is the internal resistance of the cell.

Why the terminal voltage potential difference is less than the emf of the cell?

When a cell is in closed circuit, i.e., when current is drawn from it, then the potential difference between its electrodes is called the terminal voltage. It is always less than the e.m.f. because when charge flows in a circuit, some energy is spent in the flow of charge through the electrolyte of the cell.

Is it possible that the terminal voltage will be greater than the emf of the battery?

True, yes terminal voltage of a battery can never be greater than the emf of the battery. Because due to internal resistance of the current terminal…

Is emf always greater than terminal voltage?

The emf of a cell is greater than terminal voltage because there is some potential drop across the cell due to its small internal resistance. …

Does terminal voltage equal emf?

Electromotive force (EMF) is equal to the terminal potential difference when no current flows. EMF and terminal potential difference (V) are both measured in volts, however they are not the same thing. EMF (ϵ) is the amount of energy (E) provided by the battery to each coulomb of charge (Q) passing through.

Can terminal voltage exceeds emf?

“The potential difference between the terminals of a battery will equal the emf of the battery when there is no current in the battery. 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.”

Is emf always greater than terminal PD?

The emf of a cell is greater than its terminal voltage because there is some potential drop across the cell due to its small internal resistance. …

Which condition emf of cell is less than of terminal voltage?

The terminal voltage of the cell is the potential difference across the terminals of the cell when it is connected to a circuit. This is why the terminal voltage is always less than the EMF of the same voltage source or cell. EMF = terminal voltage + internal voltage drop.

Can the terminal voltage exceeds the emf?

Why does terminal voltage decrease when current increases?

For a given emf and internal resistance, the terminal voltage decreases as the current increases due to the potential drop Ir of the internal resistance. Since the internal resistance r is in series with the load, it can significantly affect the terminal voltage and the current delivered to the load.

Why is terminal voltage of a cell less than its EMF?

When the cell delivers a current, part of the current is utilised by the internal resistance of the cell and the remaining goes in the circuit, which is known as the terminal voltage. Thus, terminal voltage is less than the emf of the cell.

How is the emf of a cell measured?

EMF of a cell is the voltage measured between the terminals of a cell when it is not connected to external circuit, that is, when it is not delivering any current. When the cell delivers a current, part of the current is utilised by the internal resistance of the cell and the remaining goes in the circuit, which is known as the terminal voltage.

Why is potential difference always less than an electromotive force?

Terminal potential difference is less than emf because when the cell is sending charge around the closed circuit, the electrolyte between cell electrodes bearing some finite resistance (we call it internal resistance ), opposes the flow of ionic current inside the cell due to which there is some potential drop inside the cell (equal to Ir ).

What is the potential difference between two terminals called?

The potential difference between the two terminals of a cell when the cell is NOT supplying any current is called EMF. The EMF is independent of the value of the internal resistance. If a cell of emf E and internal resistance r is directly connected across a Voltmeter, you can measure its EMF.