Complex numbers — does the polar form consist of a real part and a j part?

Difficulty: Easy

Correct Answer: False

Explanation:


Introduction / Context:
Complex numbers can be expressed in rectangular (Cartesian) or polar form. Correctly identifying each representation is vital for phasor arithmetic and impedance calculations.


Given Data / Assumptions:

  • Rectangular form: z = a + j * b.
  • Polar form: z = M ∠ θ (or z = M * e^{jθ}).


Concept / Approach:
The statement describes the rectangular form (real part a and imaginary part b). Polar form instead uses magnitude M = sqrt(a^2 + b^2) and angle θ = atan2(b, a). Both forms are equivalent but emphasize different operations: addition favors rectangular; multiplication/division and phase analysis favor polar.


Step-by-Step Solution:

Given z = a + j * b, compute M = sqrt(a^2 + b^2).Compute θ = atan2(b, a) in degrees or radians.Write polar: z = M ∠ θ; rectangular is recovered by a = M * cos(θ), b = M * sin(θ).


Verification / Alternative check:
Convert a numerical example: z = 3 + j4 → M = 5, θ ≈ 53.13°. Rectangular uses real/imag parts; polar uses 5 ∠ 53.13°, confirming distinct descriptions.


Why Other Options Are Wrong:

  • Choosing “True” mixes the two forms and will cause errors in multiplying/dividing phasors and converting impedances.


Common Pitfalls:
Forgetting angle units when converting; always state degrees or radians explicitly to avoid phase mistakes.


Final Answer:
False

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