Frequency is defined as number of cycles completed in

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Examoogle · Accepted Answer

One second

Explanation: Frequency is defined as the number of complete oscillations or cycles a wave completes in one second. It is measured in Hertz (Hz), where $1 	ext{ Hz} = 1 	ext{ cycle/second}$.

Working Principle: In an alternating current (AC) circuit, the source voltage changes polarity periodically. The frequency represents the rate at which the waveform repeats its cycle. Because $f = \frac{1}{T}$, where $T$ is the period in seconds, frequency is inherently a rate defined relative to a one-second time interval.

Key Formulas: $f = \frac{1}{T}$ — Frequency is the reciprocal of the time period $T$ measured in seconds.; $\omega = 2\pi f$ — Angular frequency relating frequency to rotation per second.

Key Points: The SI unit of frequency is the Hertz (Hz).; In India, the standard power supply frequency is $50 	ext{ Hz}$.; Frequency is independent of the amplitude of the signal.; Higher frequency means a shorter time period for each cycle.

Advantages: Allows synchronization of power grids.; Enables efficient design of transformers and motors.

Disadvantages: High frequencies lead to increased skin effect losses in conductors.; Electromagnetic interference (EMI) increases with frequency.

Applications: Power systems ($50/60 	ext{ Hz}$).; Radio and telecommunications ($kHz$ to $GHz$ ranges).; Clock signals in digital electronics.

Additional Info: Standard power frequency in India is $50 	ext{ Hz} \pm 3\%$.. Option B (one minute) is incorrect as it relates to RPM (rotations per minute) used in mechanical machine speed rather than electrical frequency.

Answer: A is correct — Frequency is defined as the number of cycles completed in one second, represented by the unit Hertz.

Exam Tip: Remember that $f = \frac{1}{T}$; if the frequency increases, the time period $T$ decreases proportionally, a common concept in both signal processing and machine design.

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