Base Units in SI for Electric Quantities

Steps:

• Electric field strength E has units V/m; volt V = kg m² s⁻³ A⁻¹.
• Thus, E = (kg m² s⁻³ A⁻¹)/m = kg m s⁻³ A⁻¹, using 4 base units: mass (kg), length (m), time (s), current (A).
• Power P has units W = J/s; joule J = kg m² s⁻².
• Thus, P = (kg m² s⁻²)/s = kg m² s⁻³, using 3 base units: mass (kg), length (m), time (s).

Why D is correct:

• D (4,3) matches E's 4 base units from force/charge (M L T I) and P's 3 from energy/time (M L T).

Why the others are wrong:

• A: Assumes E uses only 3 units, ignoring current (A) in volt definition.
• B: Understates E (needs 4, not 3) and P (needs 3, not 2).
• C: Incomplete option, lacks valid numbers.

Final answer: D