If a direct current of value a ampere is superimposed on an alternating current `1 = b sin omega t` flowing through a wire, what is the effective value of the resulting current in the circuit?
A. `[(a^(2)+b^(2))/(2)]^(1/2)`
B. `[a^(2)+(1)/(2)b^(2)]^(1/2)`
C. `[a^(2)+b^(2)]^(1/2)`
D. `[(1)/(2)a^(2)+b^(2)]^(1/2)`
