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 scientific term for the number of occurrences of a repeating event per unit of time.
In the context of waves, it specifically means the number of complete cycles or oscillations that pass a point in one second.
The standard unit for frequency is the Hertz (Hz), where 1 Hz is equivalent to one cycle per second.
The frequency of a sound wave determines its pitch; higher frequencies are perceived as higher-pitched or more shrill sounds.

Option A: Wavelength measures the distance of one complete wave cycle (e.g., from one peak to the next), not the number of cycles per second.
Option C: Shrillness is the subjective perception of a sound's pitch. While it is directly related to frequency (higher frequency equals higher shrillness), it is the perceptual quality, not the physical definition of vibrations per second.
Option D: Amplitude is the measure of a wave's maximum displacement from its equilibrium position. It relates to the intensity or loudness of a sound, not its rate of vibration.

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 Motion as background academic context rather than a clinical decision trigger.
Understanding wave frequency is fundamental in interpreting diagnostic tools like ultrasound, where high-frequency sound waves are used to create images of internal body structures.
In audiology, hearing tests (audiograms) measure a person's ability to hear sounds at different frequencies (pitches) and amplitudes (loudness).
What if? If a patient has difficulty hearing high-pitched sounds, it indicates a loss of sensitivity to high-frequency vibrations, a common aspect of age-related hearing loss (presbycusis). The nursing intervention would be to speak in a lower-pitched voice and face the patient to aid communication.

How to Approach the Question

First, analyze the question to identify the key definitional phrase: 'number of oscillations or vibrations per second'.
Recognize that the term 'per second' indicates a measure of rate or frequency.
Evaluate the given options based on their standard scientific definitions.
Recall that 'Frequency' is the direct measure of cycles per second, 'Wavelength' is a measure of distance, and 'Amplitude' is a measure of intensity.
Differentiate between the physical measurement (frequency) and the subjective perception (shrillness/pitch).
Conclude that 'Frequency' is the only term that precisely matches the definition provided in the question.

Concept Tested & Keywords

QRJON3jQAmSpLVKx7c09-9

E6 Psychology Morgan King 9e Part 1 p. 116-118

E6 Psychology Baron Misra 5e Part 1 p. 122-124

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.