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The terminal voltage of a cell in open circuit condition _____________is its emf.
A. more than
B. less than
C. equal to
D. square of

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Last updated date: 17th Apr 2024
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Answer
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Hint: We know that electromotive force, abbreviation E or emf, energy per unit electric charge that is imparted by an energy source, such as an electric generator or a battery. Energy is converted from one form to another in the generator or battery as the device does work on the electric charge being transferred within itself. Electromotive force is defined as the electric potential produced by either an electrochemical cell or by changing the magnetic field. EMF is the commonly used acronym for electromotive force. A generator or a battery is used for the conversion of energy from one form to another. A potential difference (voltage) can be measured between any given points in the circuit, while electromotive force exists only between the two ends of a source. Also, electromotive force is measured with an EMF meter, while voltage with a voltmeter.

Complete step by step answer
Let us know that if the electric potential difference between two locations is 1 volt, then one Coulomb of charge will gain 1 joule of potential energy when moved between those two locations. Because electric potential difference is expressed in units of volts, it is sometimes referred to as the voltage. Potential difference is a measure of how much energy is transferred between two points in a circuit.
We know that the terminal voltage of a cell in open circuit condition is equal to its emf as there is no internal voltage drop in the cell. Terminal voltage is the voltage / potential difference across the terminals of a cell or battery. If the cell/battery is not connected to circuit then the terminal voltage or potential difference is equal to the emf of the cell or battery. The voltage across the terminals of a battery, for example, is less than the emf when the battery supplies current, and it declines further as the battery is depleted or loaded down.
Thus, we can conclude that the terminal voltage of a cell in open circuit condition equal to is its emf.

Hence the correct answer is option C.

Note: Thus, we can conclude that in nature, emf is generated when magnetic field fluctuations occur through a surface. Charge separation takes place within the generator because electrons flow away from one terminal toward the other, until, in the open-circuit case, an electric field is developed that makes further charge separation impossible. The emf is equal to the work done on the charge per unit charge when there is no current flowing. Since the unit for work is the joule and the unit for charge is the coulomb, the unit for emf is the volt. 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 is the amount of energy (E) provided by the battery to each coulomb of charge passing through.