Types of Waves MCQ Quiz in मल्याळम - Objective Question with Answer for Types of Waves - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

Concept:

Earthquake

• An earthquake is a natural occurrence that causes the earth's surface to shake.

Reason for an earthquake

• The imbalance is created on the earth's surface due to the construction of dams on the rivers.
• From mining.
• From the volcano.
• from missile tests
• From hydrogen and atom bomb tests.

Explanation:

The focus of the earthquake(hypocenter) is the point beneath the earth's surface where the earthquake begins, while the epicenter is the location directly above it on the earth's surface.

Fault zone of the earth

• A fault is a fracture between two blocks of rocks.
• Blocks can move relative to each other.
• This movement might be sudden like an earthquake or it can be gradual like a creep.

Seismic zone of the earth

• A seismic zone is a term used to define a region where earthquakes are more likely to occur.
• India is divided into four seismic zones.

Therefore, The place inside the earth's crust where the earthquake originates is called the focus of the earthquake. 

Important PointsRichter Scale

•  The Richter Scale is used to measure the magnitude of an earthquake.
• This scale is expressed with a logarithmic scale.

Seismograph

• A seismograph is used to detect earthquakes.
• The study of earthquakes is known as seismology.

Mistake Points As, per the official answer key the answer is option 2, but as per the question statement option, 1 is the correct one.

CONCEPT:​

• Longitudinal Waves: Those waves whose direction of propagation and direction of disturbance is always parallel.
  • These waves produced in a medium that can sustain compressive strain. 
  • Example Sound Wave
• Transverse Waves: Those waves whose direction of propagation and direction of disturbance is always perpendicular. 
  • These waves produced in a medium that can sustain shearing strain.
  • Example: Electromagnetic Waves.

EXPLANATION:

• When Amit moves the piston in the right direction and then in the left direction.
• It creates a pulse of pressure that pushes its adjacent layer in forward and then backward direction and the waves which produced travel along with the direction of particle moves.
• So, the waves produced are longitudinal Waves.
• Hence option 1 is correct.

The Correct answer is (a) - (iii), (b) - (iv), (c) - (ii), (d) - (i)

 Key Points

• Ultraviolet Rays:
  • Ultraviolet (UV) rays have high energy, and when microorganisms are exposed to these rays, their DNA absorbs the energy, causing damage to their genetic material.
  • This makes UV light effective for sterilizing surgical instruments and other equipment, as it can kill or inactivate bacteria, viruses, and other pathogens.
• Microwaves:
  • ​Microwaves are a form of electromagnetic radiation that have wavelengths suitable for penetrating various atmospheric conditions, such as rain, clouds, and smoke.
  • This makes them highly effective in radar systems, where they are used to detect objects and measure their speed and distance.
  • Radars are crucial in air traffic control, weather forecasting, and military applications
• Infrared Waves:
  • ​Infrared waves are a type of electromagnetic radiation emitted by warm objects, including the Earth itself.
  • When solar radiation reaches the Earth's surface, it is absorbed and re-radiated as infrared radiation.
  • Greenhouse gases in the atmosphere (like carbon dioxide and water vapor) absorb some of this infrared radiation and re-emit it in all directions, warming the Earth.
  • This process is called the greenhouse effect and is crucial for maintaining the Earth's temperature.
• X-rays:
  • X-rays have very short wavelengths and are capable of penetrating solid objects.
  • They are used in X-ray crystallography, a technique that helps scientists determine the structure of crystals, such as proteins, by analyzing how X-rays diffract through them.
  • This method is essential in chemistry, biology, and materials science to understand the atomic structure of various compounds.

The correct answer is Infrared waves.

Key Points

• Electromagnetic waves are created as a result of vibrations between an electric field and a magnetic field.
• We can say that these are composed of oscillating magnetic and electric fields.
• EM Waves are- radio waves, microwaves, infrared, light, ultraviolet, X-rays, and gamma rays.
• Depending on the variations in wavelength and frequency, these waves have different applications.
• Infrared radiations are basically thermal waves.
  • These are used in electronic applications like TV remote sensors.
  • It is also used in thermal imaging cameras.

Additional Information

• Ultrasonic waves are sound waves that are greater than 20,000 Hz.
  • Humans can detect sounds in a frequency range from about 20 Hz to 20 kHz.
  • Humans cannot hear Ultrasonic waves.

• Ultraviolet radiation is widely used in industrial processes and in medical and dental practices for a variety of purposes, such as killing bacteria, creating fluorescent effects, curing inks and resins, phototherapy and sun-tanning.
• Radio waves have the longest wavelengths in the EM spectrum. These are best-known for their use in communication technologies, such as television, mobile phones, and radios.

Explanation:

• When waveforms emerge from a point source, such as a single point of light or sound, they propagate in a spherical manner.
• This means that the wavefronts, which are surfaces of constant phase, spread out equally in all directions, forming a three-dimensional sphere around the source.
• This behavior is known as spherical wave propagation.
• In contrast, a cylindrical waveform would emerge from a line source, where the wavefronts propagate in a cylindrical shape around the source.
• A plane waveform would emerge from an infinitely large source, where the wavefronts are flat and extend infinitely in all directions.
• An elliptical waveform refers to a specific shape of wavefronts, typically resulting from certain forms of interference or diffraction, but it is not the general behavior of waveforms emerging from a point source.

CONCEPT:​

• Longitudinal Waves: Those waves whose direction of propagation and direction of disturbance is always parallel.
  • These waves produced in a medium that can sustain compressive strain. 
  • Example Sound Wave
• Transverse Waves: Those waves whose direction of propagation and direction of disturbance is always perpendicular. 
  • These waves produced in a medium that can sustain shearing strain.
  • Example: Electromagnetic Waves.

EXPLANATION:

• Longitudinal Waves generally propagate in such a medium that can sustain compressive strain.
• Transverse Waves generally propagate in such a medium that can sustain shearing stress.
• Electromagnetic Waves are transverse in nature. 
• Here option 2 is the correct

Additional Information

• Electromagnetic Waves are transverse in nature and can be produced by accelerating charged particles.  

The correct answer is Electromagnetic.

Key Points​

• Electromagnetic Wave
  • The waves which require no medium to propagate are called an electromagnetic wave.
  • These waves are produced by accelerated charge.
  • These waves travel in free space with the speed of light ( 3.8* 10⁸ m/s).
  • X-rays, radio waves, ultraviolet waves are examples of electromagnetic waves.

Additional Information

• Longitudinal Waves
  • A wave in which the particles of the medium vibrate in the same direction of propagation of the wave is called a longitudinal wave.
  • It can be produced in all three media such as solids, liquids, and gases.
  • The waves which are produced in the air are always longitudinal waves.
  • Example: The waves produced in spring when it is pushed and pulled at one end are longitudinal waves.​ 
• Transverse Waves
  • A wave in which the particles of the medium vibrate perpendicular to the direction of propagation of the wave is called a transverse wave.
  • It can be produced only in solids and liquids.
  • Light is a transverse wave.
• Matter Waves
  • The waves associated with moving particles like electrons, protons, etc. are called matter waves.

CONCEPT:

• A plane wave is a special kind of wave associated with infinite parallel plane wavefronts.  
• A plane wave has a constant frequency.
• Mathematically it is written as

⇒ y = a sin(ωt - kx)     ------ (1)

Where a = amplitude, ω = angular frequency,  = frequency, and k = wave vector associated with the plane wave.

EXPLANATION:

• Equation of the wave is given as:

    ------ (2)

• On comparing the above two equations, we get

⇒ ω = 200π

• As we know, the relation between angular frequency and linear frequency is given by

• Therefore option 2 is correct.

Concept:

• Vibration: Vibration means quickly moving back and forth (or up and down) about a point.
  • Something that is vibrating may shake at the same time.
  • If it vibrates in a regular way, it may produce a musical note because it can make the air vibrate.
  • This vibration will send sound waves to the ear and to the brain.
• Amplitude: 
  • It is the distance between crest or trough and the mean position of the wave.
  • The amplitude of a sound wave is the measure of the height of the wave
  • It is the distance between crest or trough and the mean position of the wave.
  • Loudness is directly proportional to the amplitude of the sound.
  • If the amplitude of a sound wave is large, then the loudness of sound will be more.
  • If the amplitude is small, then the sound will be feeble.
• Frequency: The number of oscillations per second is known as the frequency of oscillation.
  • Its unit is hertz and is denoted by Hz.
  • The frequency of a wave in general means how frequently the particles of a medium vibrate when a wave moves through the medium.
• Time Period:  It can be said to be the time taken to do something.
  • If an event occurs repeatedly then the event is said to be periodic.
  • The time taken by the periodic event to repeat itself is known as the period.
  • The time taken by the particle to complete one vibration cycle is the time period.

Explanation:

• So, from the above, it's clear that The up-down motion around the mean position of an object is called vibration.

CONCEPT:

Longitudinal wave motion:

• It is that wave motion in which individual particles of the medium execute simple harmonic motion about their mean position along the same direction, in which the wave is propagated.
  • For example Sound waves, ultrasound waves, Tsunami waves etc.

Transverse wave motion:

• The vibration of particles in a medium and the propagation of waves are perpendicular to each other.
  • Example: Waves in the surface of the water, waves in a string, Electromagnetic waves, vibrations of guitar strings etc.

Polarization:

• This is a process by which unpolarised light is transformed into polarized light.
  • Polarisation tells about the wave nature of light, as the light wave is polarised in a particular plane.
  • The longitudinal waves cannot be polarised.

EXPLAINATION:

• The vibration of the guitar is an example of a transverse wave because in this the vibration of particles in the medium and the propagation of the wave are perpendicular to each other.
• Whereas in the case of other options the particle is vibrating in the same direction of propagation. Hence, option (3) is correct.