Physics: Waves and Radiation

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson
Download our mobile app to listen on the go
Get App

Questions and Answers

What happens to the speed of a wave when it enters a denser medium?

  • It increases.
  • It doubles.
  • It decreases. (correct)
  • It remains unchanged.

Which statement is true regarding the law of reflection?

  • The angle of reflection varies with wavelength.
  • The angle of incidence is equal to the angle of reflection. (correct)
  • The angle of incidence is always greater than the angle of reflection.
  • The angle of reflection is always zero.

Which electromagnetic wave is used for satellite transmissions and cooking?

  • X-rays
  • Ultraviolet light
  • Gamma rays
  • Microwaves (correct)

What effect does ultraviolet light exposure have on human health?

<p>Increases the risk of skin cancer. (B)</p> Signup and view all the answers

What is true about the frequency of a wave when it is refracted?

<p>It remains the same. (B)</p> Signup and view all the answers

Which color is not part of the visible spectrum?

<p>Ultraviolet (A)</p> Signup and view all the answers

Which electromagnetic wave is known for its application in medical imaging?

<p>X-rays (D)</p> Signup and view all the answers

What is the correct order of the electromagnetic spectrum from longest wavelength to shortest?

<p>Radio waves, Microwaves, Infrared, Visible light, Ultraviolet, X-rays, Gamma rays (A)</p> Signup and view all the answers

What type of wave consists of compressions and rarefactions?

<p>Longitudinal wave (B)</p> Signup and view all the answers

Which parameter measures the distance from the equilibrium position to the maximum displacement in a wave?

<p>Amplitude (B)</p> Signup and view all the answers

How is the speed of a wave calculated?

<p>Frequency × Wavelength (B)</p> Signup and view all the answers

Which of the following describes the Doppler effect?

<p>Change in observed frequency and wavelength due to motion (B)</p> Signup and view all the answers

What is the relationship between frequency and time period?

<p>Frequency is the reciprocal of time period (A)</p> Signup and view all the answers

In terms of waves, what is frequency defined as?

<p>Number of waves that pass a point per second (A)</p> Signup and view all the answers

What kind of wave has vibrations that occur at right angles to the direction of travel?

<p>Transverse wave (D)</p> Signup and view all the answers

What happens to wavefronts if the wave source is moving towards an observer?

<p>They become bunched together (B)</p> Signup and view all the answers

What is the primary reason for using protective shielding made of dense materials like lead when working with X-rays and Gamma rays?

<p>To protect against ionising radiation that can cause mutations (A)</p> Signup and view all the answers

Which statement accurately describes the behavior of light when it passes from a less optically dense medium to a more optically dense medium?

<p>The angle of refraction is less than the angle of incidence. (D)</p> Signup and view all the answers

What phenomenon occurs when light travels along the boundary of two different media at a specific critical angle?

<p>Total internal reflection (B)</p> Signup and view all the answers

Which equation relates the angle of incidence and angle of refraction to the refractive index of a medium?

<p>n1<em>sin(i) = n2</em>sin(r) (A)</p> Signup and view all the answers

What is the critical angle in the context of total internal reflection?

<p>The angle of incidence where light will reflect back into the original medium (A)</p> Signup and view all the answers

What role does optical fibre play in the transmission of information?

<p>It employs total internal reflection to carry light signals. (B)</p> Signup and view all the answers

What happens to light when it passes through a glass slab at an angle to its normal?

<p>It bends towards the normal when entering the slab. (B)</p> Signup and view all the answers

Why is reflection demonstrated in a ray diagram with a plane mirror?

<p>To represent the formation of an image through reflection (C)</p> Signup and view all the answers

What is the relationship between amplitude and loudness in sound waves?

<p>Greater amplitude results in greater loudness. (A)</p> Signup and view all the answers

How can the speed of sound in air be measured?

<p>By timing how long a sound takes to echo back from a wall. (D)</p> Signup and view all the answers

What occurs to sound waves during refraction?

<p>They bend as they pass through different mediums. (D)</p> Signup and view all the answers

Which frequencies fall within the audible range for a healthy human ear?

<p>20 Hz to 20000 Hz (D)</p> Signup and view all the answers

What characterizes the first sound wave described?

<p>Quiet and low-pitched (C)</p> Signup and view all the answers

Flashcards are hidden until you start studying

Study Notes

Ionising Radiation

  • X-rays and Gamma rays are types of ionising radiation that can lead to mutations and cancer.
  • Minimizing exposure is crucial; protective shielding should use dense materials like lead.

Light and Sound Waves

  • Light waves are transverse, characterized by peaks and troughs, and they vibrate at right angles to their direction of travel.
  • Sound waves are longitudinal, featuring compressions and rarefactions, with vibrations in the direction of travel.

Reflection and Refraction

  • Reflection occurs when light bounces off a surface, such as a plane mirror, and can be illustrated through ray diagrams.
  • Refraction happens when light passes through different media, altering its angle; denser media slow down light leading to bending towards the normal.
  • Snell's law: n1 * sin(i) = n2 * sin(r), where n represents refractive index, i is the angle of incidence, and r is the angle of refraction.

Total Internal Reflection

  • Occurs at the critical angle; when light hits a boundary at an angle greater than the critical angle, it reflects back into the denser medium, common from glass to air.
  • The critical angle is defined by n = 1/sin(c) where n is the refractive index and c is the critical angle.

Optical Fibres

  • Composed of glass with cladding, optical fibres use total internal reflection to transmit information via light, maintaining performance even when bent.

General Wave Properties

  • Waves transfer energy without transferring matter; particles oscillate around a fixed point.
  • Key terms: Amplitude (max displacement from equilibrium), Wavefront (points on wave in cycle), Frequency (waves per second), Wavelength (distance between two points), Time period (duration of one wave).

Wave Speed and Relationships

  • Wave speed equation: v = frequency × wavelength.
  • Frequency relates to time period: f = 1/T.

The Doppler Effect

  • A change in observed frequency and wavelength occurs when a wave source moves relative to an observer (e.g., a siren changing pitch when passing).

Electromagnetic Spectrum

  • Key categories in order: Radio waves, Microwaves, Infrared, Visible light (ROYGBIV), Ultraviolet, X-rays, Gamma rays.
  • All electromagnetic waves travel at high speeds in a vacuum.

Uses and Hazards of Electromagnetic Waves

  • Radio waves: Communication (TV/radio), reflected by the ionosphere.
  • Microwaves: Cooking and satellite transmissions; penetrate materials effectively.
  • Infrared: Heaters and night vision technology.
  • Visible Light: Fibre optics and photography.
  • Ultraviolet: Fluorescent lamps and tanning.
  • X-rays: Medical imaging and security; can penetrate materials.
  • Gamma radiation: Food and medical equipment sterilization.
  • Hazards: Microwaves cause internal heating, infrared leads to burns, ultraviolet raises skin cancer risk.

Sound Wave Properties

  • Audible range for humans is 20 Hz to 20,000 Hz.
  • Speed of sound can be measured by timing the echo of a sound made at a distance from a wall: speed = distance/time.
  • An oscilloscope connected to a microphone can display sound waves, showing frequency and amplitude relationship: greater amplitude = louder sound, greater frequency = higher pitch.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

More Like This

Radioprotection Chapitre I
36 questions
REVISION LECTURES 1 -3
29 questions
Electromagnetic Spectrum
10 questions

Electromagnetic Spectrum

SophisticatedForeshadowing8026 avatar
SophisticatedForeshadowing8026
Use Quizgecko on...
Browser
Browser