Average value of current and voltage over a cycle of AC is:
Correct answer: C. both
- A. positive
- B. negative
- C. both
- D. zero
Explanation
In an alternating current (AC) circuit, the current and voltage vary sinusoidally over time. The average value of an AC quantity over a complete cycle is zero because the positive and negative values cancel each other out. However, when we talk about the average *power* over a cycle, it is not zero.- A) Positive: The average value of the current or voltage alone is not positive over a cycle. - B) Negative: Similarly, the average value of the current or voltage alone is not negative over a cycle. - D) Zero: While the average value of current or voltage alone is zero, it's crucial to note that the average power (product of voltage and current) is not zero. The power alternates between positive and negative values, but when averaged over a cycle, it gives a non-zero result.So, option C is correct because the average value of both current and voltage over a cycle is zero, but the average power is not zero.
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Electromagnetic waves consist of mutually perpendicular, oscillating electric and magnetic fields that also remain perpendicular to the direction of propagation. They travel through vacuum at the speed of light and include radio waves, microwaves, infrared, visible, ultraviolet, X-rays and gamma rays. Unlike mechanical waves, they do not require a material medium.
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