Which of the following statements are true regarding alternating current?

(A) In an a.c. circuit containing resistance only, a.c. power is expressed in the same form as d.c. power ($P = I^2R$), using a special value of current called root mean square (rms) or effective current, which is denoted by $I_{rms}$
(B) a phasor is a vector.
(C) resonance phenomenon is exhibited by a circuit even if both L and C are not present in the circuit.
(D) for circuits used for transporting electric power, a low power factor implies less power loss in transmission.

Choose the correct answer from the options given below:

(A) and (B) only

The correct answer is Option (2) → (A) and (B) only

(A) True → In a pure resistive a.c. circuit, power is $P = I_{\text{rms}}^2 R$, same form as in d.c.

(B) True → A phasor is a rotating vector-like representation in complex plane.

(C) False → Resonance requires both $L$ and $C$ in the circuit.

(D) False → A low power factor means more power loss in transmission, not less.

Answer: (A) and (B) is true.