1Which of these has the same dimensions as potential difference?
Potential difference and electric potential both have the dimensions [M L² T⁻³ A⁻¹].
ElectrostaticsClass 12, Electrostatic Potential and Capacitance
Dimensional formula of Potential difference
[M L2 T-3 A-1]
The work done per unit charge in moving it between two points. It has the dimension of electric potential.
How to get the dimensional formula of potential difference
- Start from the definition: potential difference = work / electric charge.
- velocity = length / time, so velocity is [L] / [T] = [L T-1].
- acceleration = velocity / time, so acceleration is [L T-1] / [T] = [L T-2].
- force = mass × acceleration, so force is [M] × [L T-2] = [M L T-2].
- displacement = length, so displacement is [L] = [L].
- work = force × displacement, so work is [M L T-2] × [L] = [M L2 T-2].
- electric charge = electric current × time, so electric charge is [A] × [T] = [T A].
- Put in the dimension of each part: [M L2 T-2] / [T A].
- Add the powers of each base quantity: [M L2 T-3 A-1].
Quantities with the dimensions [M L² T⁻³ A⁻¹]
Equal dimensions do not make them the same quantity. Compare potential difference with the others in the full grid.
Three questions on potential difference
2What is the SI unit of potential difference?
The SI unit of potential difference is the volt (V).
3Which one has different dimensions from the others?
Electric dipole moment is [L T A]. The other three are all [M L² T⁻³ A⁻¹].
Potential difference: quick answers
What is the dimensional formula of potential difference?
The dimensional formula of potential difference is [M L² T⁻³ A⁻¹]. It comes from potential difference = work / electric charge.
What is the SI unit of potential difference?
The SI unit of potential difference is the volt (V).
Which quantities have the same dimensions as potential difference?
Potential difference shares [M L² T⁻³ A⁻¹] with electric potential, electromotive force (emf), stopping potential. Equal dimensions do not make them the same quantity.