Peak-to-peak computation: If the peak of a sine wave is 13 V, what is the peak-to-peak voltage (Vpp)?
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A26 V
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B13 V
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C6.5 V
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Dnone of the above
Answer
Correct Answer: 26 V
Explanation
Introduction / Context:Engineers often switch between peak (Vp), peak-to-peak (Vpp), and RMS values. Peak-to-peak measures the total excursion from the most negative to the most positive instant of a sinusoid. This item checks quick conversion from Vp to Vpp.
Given Data / Assumptions:
- Peak voltage Vp = 13 V.
- Ideal sinusoid centered at 0 V (no DC offset).
Concept / Approach:
For a symmetric sine wave centered at zero, negative peak is −Vp and positive peak is +Vp. Therefore, Vpp = (+Vp) − (−Vp) = 2 * Vp.
Step-by-Step Solution:
Use identity: Vpp = 2 * Vp.Compute: Vpp = 2 * 13 V = 26 V.Report result exactly: 26 V.Verification / Alternative check:
If RMS were needed, Vrms = Vp/√2 ≈ 9.19 V, and Vpp would still be 2 * 13 V = 26 V. Different amplitude measures serve different purposes, but Vpp depends only on Vp for a centered sine.
Why Other Options Are Wrong:
13 V is the peak, not peak-to-peak. 6.5 V would be Vp/2. ‘‘none of the above’’ is incorrect because 26 V is valid.
Common Pitfalls:
Confusing RMS or average with peak-to-peak; forgetting the factor of 2 when converting.
Final Answer:
26 V