11.6-11.9 Waves 1 Quizlet Cards

Question 1

What is the difference between mechanical waves and electromagnetic waves?

Answer 1

EM waves don’t require a medium.

Question 2

What is an electromagnetic wave?

Answer 2

An oscillation of the electric and magentic fields at right angles to each other.

Question 3

What is the speed of all EM waves in a vacuum/air?

Answer 3

3x10⁸ms⁻¹

Question 4

List the regions of the EM spectrum in order of increasing wavelength.

Answer 4

Radio waves, Microwaves, Infrared, Visible Light, Ultraviolet, X-rays, Gamma rays

Question 5

Which two regions of the EM spectrum overlap?

Answer 5

X-rays and gamma rays.

Question 6

State the range of wavelengths (in powers of 10) of radio waves

Answer 6

> 10⁻¹

Question 7

State the range of wavelengths (in powers of 10) of microwaves

Answer 7

10⁻¹ - 10⁻³

Question 8

State the range of wavelengths (in powers of 10) of infrared

Answer 8

10⁻³ - 10⁻⁶

Question 9

State the range of wavelengths of visible light

Answer 9

7x10⁻⁷ - 4x10⁻⁷

Question 10

State the range of wavelengths (in powers of 10) of ultraviolet

Answer 10

10⁻⁷ - 10⁻⁸

Question 11

State the range of wavelengths (in powers of 10) of X-rays

Answer 11

10⁻⁸ - 10⁻¹³

Question 12

State the range of wavelengths (in powers of 10) of gamma rays

Answer 12

<10⁻¹⁰

Question 13

Why can’t longitudinal waves be polarised?

Answer 13

Longitudinal waves already only have a single driection of oscillation.

Question 14

What is the effect of a polarising filter?

Answer 14

It only transmits the component of the oscillations parallel to the filter

Question 15

What is the effect of perpendicular polarising filters

Answer 15

No light is transmitted

Question 16

Give a use of polarising filters.

Answer 16

LCD screens, 3D TV, polarimetry in manufacturing, anti-glare sunglasses

Question 17

What effect does reflection have on the polarisation of light?

Answer 17

Reflected light is partially polarised in the plane of the surface.

Question 18

What effect does scattering light have on polarisation?

Answer 18

Scattered light is polarised

Question 19

Which wave property always remains constant when a wave travels from one medium to another?

Answer 19

Frequency

Question 20

When entering a material with a higher refractive index what happens to wave speed?

Answer 20

decreases

Question 21

When entering a material with a lower refractive index what happens to wavelength?

Answer 21

increases

Question 22

What is the definition of the refractive index of a material

Answer 22

Speed of light in a vacuum/Speed of light in material

Question 23

What are the angles of incidence and refraction measured relative to?

Answer 23

The normal to the boundary

Question 24

Which way do waves refract when entering a material with a higher refractive index?

Answer 24

Toward the normal

Question 25

Which way do waves refract when entering a material with a lower refractive index?

Answer 25

Away from the normal

Question 26

What is the angle of refraction at the critical angle?

Answer 26

Ninety degrees

Question 27

What are the conditions required for total internal reflection?

Answer 27

Wave must be travelling in a material with a higher index and meeting a boundary with a material of lower refractive index. The angle of incidence must be greater than the critical angle.