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As we’ve seen, electric circuits are all about the movement of charge between different locations and the corresponding loss and gain of energy that occurs as a result of this movement. The influence of an electrochemical cell or collection of cells (i.e., a battery) in a simple circuit can be correctly understood with a clear understanding of electric potential difference. The cells purely provide the energy required to perform work on the charge in order to move it from the negative to the positive terminal. The cell could indeed maintain an electric potential difference across the two ends of the external circuit by providing energy to the charge. The potential difference between two points in a circuit is the difference in the amount of energy that charge carriers have. Potential difference (p.d.) is also recognised as voltage and is measured in volts (V). When charge carriers pass through electrical components in a circuit, energy is transferred to them. To assess potential differences, we use a voltmeter (or voltage).
The potential difference (also recognised as voltage) has been equal to the current multiplied by the resistance. Whenever one Coulomb of charge flows between two points in a circuit, a potential difference of one Volt equals one Joule of energy. Once two negative charges are brought close together, they repel each other. However, when a positive and a negative charge are brought close together, they attract. Whenever these two diametrically opposed charges are combined, they can be put to use. This is why we require a positive (+) and a negative (–) to turn on a light bulb or any electrical tool, equipment, mobile phone, or home appliance. The capacity of charged particles to do work is referred to as their electric potential.
Voltmeters are devices that measure the potential difference (voltage) between two points in a circuit. Voltmeters should always be connected in parallel (on a different branch of the circuit) to the two points being measured.
Dimensional Formula of Potential Difference
The dimensional formula of potential difference can be represented as:
[M1 L2 T-3 I-1]
Here,
M = Mass
I = Current
L = Length
T = Time
Derivation:
We have, potential Difference = work done × [charge]-1 . . . . (1)
As because, Work done = Force (M × a) × Displacement . . . (2)
Now, the dimensional formula of,
Mass = [M1 L0 T0] . . . . (3)
Displacement = [M0 L1 T0] . . . . (4)
Acceleration = [M0 L1 T-2] . . . . . (5)
When substituting equation (3), (4) and (5) in equation (2) we get,
Work done = [M1 L0 T0] × [M0 L1 T-2] × [M0 L1 T0]
Thus, the dimensions of Work done = [M1 L2 T-2] . . . . (6)
As we know, Charge = Current × time
Therefore, the dimensional formula of charge = [M0 L0 T1 I1] . . . . (7)
When substituting equation (6) and (7) in equation (1) we get,
Potential Difference = work done × [charge]-1
That is, P.D = [M1 L2 T-2] × [M0 L0 T1 I1]-1 = [M1 L2 T-3 I-1] .
Thus, the Potential difference has been dimensionally represented as [M1 L2 T-3 I-1].
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FAQs
How do you determine electric Potential difference by Ohm’s Law?
To begin, determine the amount of current flowing through a circuit. The amount of resistance in the circuit is then calculated. Finally, multiply the current in the circuit by the resistance in the circuit.
What is the potential difference exactly?
A supply's potential difference (or voltage) is a measure of the energy delivered to charge carriers in a circuit.
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