waves

Question 1

What is Wavelength (λ)?

Answer 1

Distance between two crests or troughs, measured in meters.

Question 2

What is Amplitude?

Answer 2

Height of the wave from the rest position; determines wave energy.

Question 3

What are Crest and Trough?

Answer 3

The highest and lowest points of a wave.

Question 4

What is Frequency (f)?

Answer 4

Number of wave cycles per second, measured in Hertz (Hz).

Question 5

How does frequency relate to energy?

Answer 5

Higher frequency = higher energy, lower frequency = lower energy.

Question 6

What are Mechanical Waves?

Answer 6

Waves that require a medium (air, water, solid) to travel.

Question 7

What are examples of Mechanical Waves?

Answer 7

Sound waves, water waves, seismic waves.

Question 8

What are Electromagnetic Waves?

Answer 8

Waves that do not require a medium; can travel through space.

Question 9

What are examples of Electromagnetic Waves?

Answer 9

Radio waves, microwaves, infrared, visible light, UV, X-rays, gamma rays.

Question 10

What is Reflection?

Answer 10

A wave bounces off a surface at the same angle it arrived (e.g., echo, mirror reflection).

Question 11

What is Refraction?

Answer 11

A wave changes speed and direction when entering a new medium (e.g., light bending in water).

Question 12

What is Resonance?

Answer 12

When an object vibrates at its natural frequency due to an external wave, amplifying its motion (e.g., breaking a glass with sound).

Question 13

What is Scattering?

Answer 13

Waves spread out after hitting particles (e.g., blue sky due to light scattering).

Question 14

What is the Doppler Effect?

Answer 14

Frequency changes when the wave source moves relative to the observer (e.g., ambulance siren pitch shift).

Question 15

What is the Electromagnetic Spectrum?

Answer 15

The EM spectrum includes all types of electromagnetic waves, arranged by wavelength and frequency.

Question 16

What are Radio Waves?

Answer 16

Long wavelength, low frequency, low energy waves used in communication (radio, TV, Wi-Fi).

Question 17

What are Microwaves?

Answer 17

Used in cooking and mobile phones.

Question 18

What is Infrared (IR)?

Answer 18

Heat radiation, night vision.

Question 19

What is Visible Light?

Answer 19

The only part of the spectrum that human eyes can see (400-700 nm).

Question 20

What are the colors of Visible Light?

Answer 20

Red, Orange, Yellow, Green, Blue, Indigo, Violet.

Question 21

What is Ultraviolet (UV)?

Answer 21

Causes sunburn, used in sterilization.

Question 22

What are X-rays?

Answer 22

Used in medical imaging.

Question 23

What are Gamma Rays?

Answer 23

Highest energy, used in cancer treatment.

Question 24

What is a Continuous Spectrum?

Answer 24

All wavelengths of visible light, like sunlight.

Question 25

What is an Absorption Spectrum?

Answer 25

A continuous spectrum with missing wavelengths (dark lines). ## Footnote Formed when light passes through a gas, and certain wavelengths are absorbed; used to identify elements in stars.

Question 26

What is an Emission Spectrum?

Answer 26

Bright lines on a dark background, showing specific wavelengths emitted by an element when electrons fall to lower energy levels.

Question 27

What are examples of Wireless Communication?

Answer 27

Wi-Fi, Bluetooth, Mobile Phones.

Question 28

What is a Base Station?

Answer 28

A communication tower that connects mobile phones to a network.

Question 29

What is the Binary System?

Answer 29

Digital data is stored as 1s and 0s (on and off signals).

Question 30

What is Modulation?

Answer 30

A method to encode digital signals on a carrier wave.

Question 31

What is Amplitude Modulation (AM)?

Answer 31

Changes wave height.

Question 32

What is Frequency Modulation (FM)?

Answer 32

Changes wave frequency.

Question 33

What are the types of Radioactive Decay?

Answer 33

Alpha (α), Beta (β), Gamma (γ).

Question 34

What is Alpha decay?

Answer 34

Heavy, slow, stopped by paper.

Question 35

What is Beta decay?

Answer 35

Lighter, penetrates skin, stopped by aluminum.

Question 36

What is Gamma decay?

Answer 36

High energy, deeply penetrating, stopped by lead.

Question 37

What are uses of Radiation?

Answer 37

Cancer treatment, sterilization of medical equipment, radiocarbon dating.

Question 38

What are the effects of Ionizing Radiation?

Answer 38

Can damage DNA, leading to mutations; high exposure increases cancer risk.

Question 39

What is the Big Bang?

Answer 39

The universe began ~13.8 billion years ago from an extremely hot and dense state.

Question 40

What is Redshift?

Answer 40

Light from distant galaxies is stretched, showing the universe is expanding.

Question 41

What is Cosmic Background Radiation?

Answer 41

Leftover heat from the early universe, detected as microwave radiation.

Question 42

What is Element Abundance?

Answer 42

The universe has mostly hydrogen and helium, as predicted.