3.18 Table of various Quantities - Current Electricity - Class 12 Physics

3.18 TABLE of various quantities:

Physical Quantity Symbol Dimensions Unit Remark
Electric current I [A] A SI base unit
Charge Q, q [T A] C
Voltage, Electric potential difference V [M L^2 T^−3 A^−1] V Work/charge
Electromotive force ε [M L^2 T^−3 A^−1] V Work/charge
Resistance R [M L^2 T^−3 A^−2] Ω R = V/I
Resistivity ρ [M L^3 T^−3 A^−2] Ω m R = ρl/A
Electrical conductivity σ [M^−1 L^−3 T^3 A^2] S σ = 1/ρ
Electric field E vector [M L T^−3 A^−1] V m^−1 Electric force/ charge
Drift speed Vd [L T^−1] m s^−1 vd = e E τ /m
Relaxation time τ [T] s
Current density j vector [L^−2 A] A m^−2 current/area
Mobility μ [M L^3 T^−4 A^-1] m^2V^−1s^−1 vd /E