Dimensional formula of Mobility

How to get the dimensional formula of mobility

1. Start from the definition: mobility = velocity / electric field.
2. velocity = length / time, so velocity is [L] / [T] = [L T^-1].
3. acceleration = velocity / time, so acceleration is [L T^-1] / [T] = [L T^-2].
4. force = mass × acceleration, so force is [M] × [L T^-2] = [M L T^-2].
5. electric charge = electric current × time, so electric charge is [A] × [T] = [T A].
6. electric field = force / electric charge, so electric field is [M L T^-2] / [T A] = [M L T^-3 A^-1].
7. Put in the dimension of each part: [L T^-1] / [M L T^-3 A^-1].
8. Add the powers of each base quantity: [M^-1 T² A].

Three questions on mobility

Related quantities

• J Current density [L⁻² A]
• R Electrical resistance [M L² T⁻³ A⁻²]
• G Conductance [M⁻¹ L⁻² T³ A²]
• ρ Resistivity [M L³ T⁻³ A⁻²]
• σ Conductivity [M⁻¹ L⁻³ T³ A²]
• α Temperature coefficient of resistance [K⁻¹]