Phasor concept: In AC analysis, a phasor is used to represent which of the following properties of a sinusoidal quantity?

Introduction / Context:
Phasors are rotating vectors used to represent steady-state sinusoidal signals in the frequency domain. They compress time-domain sinusoids into a complex-number form that captures both magnitude and phase at a single frequency, simplifying circuit analysis with impedances.

Given Data / Assumptions:

• Sinusoidal steady state is assumed (single frequency).
• We are representing voltage or current as a phasor.
• No transient or non-sinusoidal content is considered.

Concept / Approach:

A phasor can be written as M∠φ or as a complex number M(cosφ + j sinφ). It encodes both magnitude M and phase angle φ relative to a reference sinusoid, while the time dependence is suppressed.

Step-by-Step Solution:

Verification / Alternative check:

Converting back to time domain: v(t) = Re{V∠φ * e^{jωt}} = Vm cos(ωt + φ). The phasor V∠φ determines both Vm and φ, confirming the two key pieces of information.

Why Other Options Are Wrong:

Phase angle only or magnitude only omit essential information. 'Width' is irrelevant to phasor representation and pertains to pulses, not sinusoids.

Common Pitfalls:

Confusing phasor magnitude with RMS vs peak (either can be used consistently); treating time-varying transients as phasors (phasors require steady state).

Final Answer:

the magnitude and the phase angle of a quantity