The number of oscillations or vibrations per second is called the ________?

Appeared in: RRB Nsg. Superintendent 21 July 2019 (shift 1st)

Explanation

Frequency is the physical quantity that measures the number of complete oscillations or vibrations occurring in a single second.
The standard unit for frequency is Hertz (Hz), where 1 Hz is equivalent to one cycle per second.
This concept is fundamental to describing any periodic motion, including sound waves, light waves, and alternating electrical currents.

Option A: Wavelength is a measure of distance, not rate. It describes the spatial length of a single wave cycle.
Option C: Shrillness (or pitch) is the subjective human perception of frequency. It is a qualitative characteristic, not the quantitative physical measurement.
Option D: Amplitude measures the intensity or energy of a wave, which is perceived as loudness in sound. It represents the maximum displacement from the equilibrium position.

Visual 1: Diagram - An annotated sine wave. The diagram should clearly label the 'Wavelength' as the horizontal distance of one full cycle and the 'Amplitude' as the vertical height from the center line to the peak. It should also show multiple cycles over a time axis to illustrate frequency.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Definition of Frequency in Wave Physics as background academic context rather than a clinical decision trigger.
Understanding frequency is crucial in various medical technologies. For example, in diagnostic ultrasound, the frequency of the sound waves determines both the image resolution and the depth of tissue penetration.
In audiology, hearing tests (audiograms) measure a person's ability to hear sounds at different frequencies (pitches) and amplitudes (loudness) to diagnose hearing loss.
What if the question asked for the property related to the 'loudness' of a sound? In that case, the correct answer would be 'Amplitude', which corresponds to the intensity of the sound wave.

How to Approach the Question

This is a factual recall question that tests your knowledge of a basic physics definition.
First, break down the question stem: 'number of oscillations or vibrations' refers to a repeating cycle, and 'per second' indicates a rate over time.
Combine these concepts: 'cycles per second'.
Evaluate each option based on this understanding.
Wavelength is a measure of distance.
Frequency is defined as cycles per unit of time (e.g., per second). This matches the question.

Concept Tested & Keywords

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Practise the full RRB Nsg. Superintendent 21 July 2019 (shift 1st)

Attempt every question from this paper in a timed mock, then review the full solution for each one.