MISA Waves and Electromagnetic Radiation 3

Question 1

What is diffraction?

Accepted Answer

The spreading of waves as they pass through an opening or around an obstacle

Answer

The change in wave speed when entering a new medium

Answer

The reflection of waves off a smooth surface

Answer

The increase in wave amplitude near a resonant frequency

Question 2

The Doppler effect describes:

Accepted Answer

The apparent change in frequency of a wave due to relative motion between the source and observer

Answer

The decrease in wave speed as a source moves away

Answer

The bending of waves around obstacles

Answer

The increase in wave amplitude as a source approaches

Question 3

What is the period of a wave?

Accepted Answer

The time required to complete one full wave cycle

Answer

The number of cycles per second

Answer

The distance between two consecutive crests

Answer

The maximum displacement of the medium

Question 4

Which type of electromagnetic radiation is used in medical imaging to view bones inside the body?

Accepted Answer

X-rays

Answer

Ultraviolet rays

Answer

Microwaves

Answer

Infrared radiation

Question 5

A wave has a frequency of 200 Hz and a speed of 400 m/s. What is its wavelength?

Accepted Answer

2 m

Answer

80,000 m

Answer

0.5 m

Answer

200 m

Question 6

Ultraviolet (UV) radiation from the Sun can cause sunburn because it:

Accepted Answer

Has higher frequency than visible light and carries enough energy to damage skin cells

Answer

Has a longer wavelength than visible light and carries more heat energy

Answer

Travels faster than visible light and delivers energy more quickly

Answer

Reflects off the atmosphere and is concentrated on Earth's surface

Question 7

Which statement best explains why electromagnetic waves can travel through the vacuum of space but sound waves cannot?

Accepted Answer

Electromagnetic waves are self-propagating disturbances in electric and magnetic fields and need no medium, whereas sound waves require matter to transmit compressions

Answer

Electromagnetic waves travel faster than sound, allowing them to cross empty space

Answer

Sound waves lose energy quickly while electromagnetic waves do not

Answer

Sound waves have too low a frequency to travel through a vacuum