What is Frequency?

If you are doing engineering, studying physics, or electronics, you must have read the word frequency. It quantifies the repetitions of a recurring event within a specific timeframe. Although it appears straightforward, frequency carries significant implications across diverse domains, including electrical engineering, musical theory, and more. In this article, we will understand what is it, why it is used, and what terms are used for calculating frequency in an easy manner.

What is Frequency?

In its essence, frequency tells us how frequently an event recurs or a phenomenon repeats itself within a designated duration. Typically measured in Hertz (Hz), where one Hertz corresponds to a solitary cycle or oscillation per second.

Frequency

There are various types of frequencies which are as follows:

• Electrical Frequency
• Rotational Frequency
• Angular Frequency
• Spatial Frequency
• Sound Frequency
• Light Frequency
• Mechanical Vibrations
• Communication Systems

Electrical Frequency

In the realm of electrical engineering, frequency refers to the count of alternating current (AC) cycles are happening within a single second.

Rotational Frequency

It tells us how fast the object is revolving or rotating around its axis in a specified time duration. It tells us how many full rotations are completed by an object in an given interval of time.

Mathematical Representation

Rotational Frequency (ω) is computed by dividing the angular displacement (θ) by the time interval (t):

Rotational frequency is typically measured in radians per second (rad/s).

Angular Frequency

It tells us about the rate of rotating means how many radians an object is rotating per unit time interval. It is commonly employed in the analysis of wave patterns and harmonic motion.

Angular Frequency (ω) is determined by the change in phase angle (φ) over time (t):

Spatial Frequency

It denotes the number of oscillations or oscillatory cycles covered in a spatial distance. Its commonly used in image processing, signal analysis.

Spatial Frequency (f) is calculated as the reciprocal of the spatial period (λ), which is the distance over which one complete cycle of the waveform occurs:

Sound Frequency

Within the domain of sound waves, frequency dictates the pitch of a sound. Higher frequencies correlate with higher-pitched sounds, while lower frequencies yield lower-pitched auditory experiences. Musical notes often find their descriptions through their respective frequencies.

Light Frequency

In optics, frequency pertains to the color of light. Diverse light colors manifest distinct frequencies, with red boasting a lower frequency than blue, for instance.

Mechanical Vibrations

Frequency equally finds application in delineating mechanical oscillations, be it the resonation of a guitar string or the pendulum’s swaying.

Communication Systems

In telecommunications, frequency defines the range of radio waves allocated to distinct communication services. Everyone use internet wifi and many wireless devices. It finds the great use of frequency because of waves transportation.

Important Terminologies of Frequency

Before moving into the ways of determining and calculating frequency, it is essential to understand critical terminology associated with this concept.

More vs Less Frequency

• Period (T): Period designates the timespan required to complete a full cycle or oscillation. It represents the reciprocal of frequency, denoted as , where ‘f’ signifies frequency in Hertz. For instance, if a wave boasts a frequency of 5 Hz, its period spans 1/5 seconds or 0.2 seconds.

• Amplitude: Amplitude signifies the maximum displacement of a wave from its equilibrium position. In the context of sound waves, it establishes sound loudness, while in electrical signals, it embodies peak voltage or current levels.

• Wavelength (λ): Wavelength conveys the spatial gap between consecutive points in a wave that align in phase, like two crests or two troughs. Wavelength manifests an inverse correlation with frequency, expressed as , with ‘c’ representing wave speed.

• Angular Frequency (ω): Angular frequency offers an alternative way of articulating frequency, frequently employed in trigonometric equations. It corresponds to frequency through ω = 2πf, where ‘ω’ denotes angular frequency in radians per second, and ‘f’ signifies frequency in Hertz.

• Harmonics: Within sound or waveforms, harmonics materialize as whole-number multiples of the fundamental frequency. They enrich sound or wave character. For instance, the second harmonic of a vibrating guitar string oscillates at twice the frequency of the primary tone.

How to Determine Frequency?

Step 1: Wave or Signal Nature

Initiate by identifying the nature of the wave or signal under examination. Is it an electrical waveform, an acoustic wave, or an alternate entity? This contextual comprehension is instrumental in employing appropriate formulas and methodologies.

Step 2: Evaluate Period

If dealing with a wave or oscillation, find out the time interval required to complete a single cycle. This duration is known as period(T)

Step 3: Compute Frequency

Leverage the frequency formula as follows:

For electrical signals:

For sound waves:

For Angular Frequency (ω) = 2π × Frequency (f)

For Wave Speed (v) = Frequency (f) × Wavelength (λ)

Step 4: Unify Units and Conversion

Ensure harmonized units across measurements and calculations. Hertz (Hz) signifies the standard frequency unit, though diverse units like kilohertz (kHz) or megahertz (MHz) might be encountered. Conversions may be requisite.

Hertz (Hz) to Kilohertz (kHz):

Hertz (Hz) to Megahertz (MHz):

Kilohertz (kHz) to Hertz (Hz): Hertz (Hz) = Kilohertz (kHz) × 1,000

Megahertz (MHz) to Hertz (Hz): Hertz (Hz) = Megahertz (MHz) × 1,000,000

Step 5: Interpretation

To find out the specific frequency it should be interpreted within the context of your specific problem or application. For instance, in the case of an electrical signal, it can be instrumental in circuit design or waveform analysis.

Solved Examples

Q.1: Suppose you are grappling with an alternating current (AC) signal, and your measurements unveil a period of 0.02 seconds. Determine the frequency?

The frequency of this AC signal amounts to 50 Hertz.

Q.2: Imagine you are studying a musical instrument’s sound production. You have gauged the speed of sound in air to be approximately 343 meters per second, and the wavelength of a specific note measures 0.7 meters. What is the frequency?

The frequency of this musical note equates to 490 Hertz.

Q.3: Within the domain of telecommunications, radio waves play a pivotal role. Contemplate working with a radio signal characterized by a wavelength of 3 meters. Find the frequency.

The frequency of this radio wave stands at 100 megahertz.

Q.4: Suppose you are provided a harmonic oscillator device of frequency 2Hz. How would you find its angular frequency?

Angular Frequency (ω) = 2π × Frequency (f)

Frequency (f) = 2 Hz

ω = 2π × 2 Hz = 4π radians per second

So, the angular frequency of this harmonic oscillator is 4π radians per second.

Q.5: Imagine that you are on a nice beach with your friend and seeing waves in water and you try to find the speed of waves. If you know the frequency and wavelength of those waves are 5Hz and 2m respectively. So how would you find speed of waves?

Using the formula: Wave Speed (v) = Frequency (f) × Wavelength (λ)

Frequency (f) = 5 Hz

Wavelength (λ) = 2 meters

v = 5 Hz × 2 meters = 10 meters per second

So, speed of these water waves is 10 meters per second

Advantages and Disadvantages of Frequency

Here, we have some list of advantages and disadvantages of frequency given below :

Advantages

• More data can be carried using high frequency which can help in high-speed data transmission.
• Ultrasound waves at high frequencies are used in medical imaging for visualizing internal structures.
• High-frequency signals can transmit data quickly, which is crucial for modern communication systems.
• Higher frequencies can provide greater bandwidth for data transmission, enabling more information to be sent simultaneously.

Disadvantages

• High-frequency waves do not travel long distances and can be easily absorbed or blocked by obstacles, necessitating more infrastructure.
• High-frequency sound waves can be unpleasant or damaging to human hearing.
• High-frequency signals experience more attenuation in transmission, limiting their range and requiring more repeaters/amplifiers.
• High-frequency signals are more susceptible to interference, reducing signal quality.

Applications of Frequency

The concept of frequency is used in various subjects such as:

Physics and Engineering

• Frequency can be used for wave examination in physics studying different types of waves such as electromagnetic, mechanical and sound waves. Frequency helps us in determining properties such as wavelength and speed.
• Engineers employ frequency analysis to design structures and systems that can resonate at specific frequencies, preventing undesirable resonances in objects like musical instruments and bridges.
• Frequency plays a pivotal role in circuit design, oscillator development, and communication system operation, as seen in radio and television.

Medicine and Biology

• Medical Imaging techniques such as magnetic resource locator (MRI) and ultrasound depends on frequency for generating images of internal structures by sending waves.
• Electroencephalography (EEG): EEG measures brain electrical activity, contributing to neuroscience research and clinical diagnoses.

Geophysics

• Study of seismology where waves produced by earthquakes are of very different frequency ranges, so frequency helps scientists in understanding earth structure and seismic nature.

Music and Entertainment

• Movie and Music makers use the frequency analysis for mixing audio recordings.
• Sound effects and music are designed with specific frequencies to enhance the cinematic and gaming experience.

Environmental Science

• Climate scientists employ frequency analysis to study long-term weather patterns and extreme events, such as hurricanes and droughts.
• Ecologists utilize frequency data to investigate species distribution and behavior in different ecosystems.

Conclusion

In this article, we have studied various aspects of frequency in terms of electrical systems, sound, mechanical systems, communications systems, and many more. In every domain, the definition of the frequency changes depending on the applications.

FAQs on Frequency

1. What kind of EM waves are used for uncovering hidden objects?

High frequency EM waves are used for finding artifacts or hidden objects. Ground-penetrating radar (GPR) technology is used for these purposes.

2. In what way does the utilization of particular frequencies affect brainwave entrainment techniques and the facilitation of altered states of consciousness during meditation practices?

Brainwave entrainment techniques adeptly leverage specific audio frequencies to guide and synchronize brainwave patterns, thus facilitating desired mental states like relaxation, concentration, and altered states of consciousness during meditation.

3. What’s the importance of Earth’s Schumann Resonance frequency?

The Earth’s Schumann Resonance is the resonance electromagnetic frequency of earth which is calculated to be 7.83 Hz. Its really important to be studied because it tells about ionosphere and also about the atmospheric conditions. It provides insights into natural electromagnetic phenomena.

4. How is frequency related to sound?

Frequency in sound determines the pitch. High frequencies correspond to high-pitched sounds, while low frequencies result in low-pitched sounds.