20) C

** A is a measure of electrical power.**P = VI

I = Q / t

Substituting (I = Q / t) in the equation P = VI,

P = (Q / t) x V = QV / t

** B is a measure of electrical power. **P = IV

V = IR

Substituting (V = IR) in the equation P = VI,

P = I x IR = I²R

** C is not a measure of electrical power. **There is no way to equate P = (Q²R / t)

** D is a measure of electrical power. **P = VI is the most basic formula for power and it something that needs to be learnt.

** E is a measure of electrical power. **P = IV

I = V / R

Substituting (I = V / R) in the equation P = VI,

P = V x (V / R) = (V² / R)