5. EM Spectrum

Question 1

What type of wave is every member of the EM spectrum?

Answer 1

Transverse

Question 2

What is the definition of a transverse wave?

Answer 2

The wave oscillates perpendicular to the direction it is travelling in.

Question 3

What is the definition of a longitudinal wave?

Answer 3

The wave oscillates in the same direction it is travelling in.

Question 4

What speed to ALL EM waves travel at?

Answer 4

3x10⁸ ms^-1

Question 5

State all the members of the EM spectrum

Answer 5

Radiowaves
Microwaves
Infrared
Visible light
Ultraviolet
X-rays
Gamma rays

Question 6

Which member of the EM spectrum has the highest frequency?

Answer 6

Gamma rays

Question 7

Which member of the EM spectrum has the lowest frequency?

Answer 7

Radiowaves

Question 8

Which member of the EM spectrum has the longest wavelength?

Answer 8

Radiowaves

Question 9

Which member of the EM spectrum has the shortest wavelength?

Answer 9

Gamma rays

Question 10

Which member of the EM spectrum diffracts the most?

Answer 10

Radiowaves

Long wavelengths diffract more than short wavelengths.

Question 11

State a detector of radiowaves

Answer 11

Aerials

Question 12

State a detector of microwaves

Answer 12

Aerials

Question 13

State a detector of infrared

Answer 13

Photodiode

Question 14

State a detector of visible light

Answer 14

Photodiode

Question 15

State a detector of ultraviolet

Answer 15

Photographic film

Question 16

State a detector of x-rays

Answer 16

Photographic film

Question 17

State a detector of gamma rays

Answer 17

Geiger-muller counter

Question 18

State a medical and an industrial use of radiowaves

Answer 18

Medical - MRI machines
Industrial - Submarine communication

Question 19

State a medical and an industrial use of microwaves

Answer 19

Medical - Microwave thermotherapy
Industrial - Wi-Fi

Question 20

State a medical and an industrial use of infrared

Answer 20

Medical - Detecting inflammation
Industrial - Search and rescue

Question 21

State a medical and an industrial use of visible light

Answer 21

Medical - Laser eye surgery
Industrial - Traffic lights

Question 22

State a medical and an industrial use of ultraviolet

Answer 22

Medical - treating acne
Industrial - Crime scene investigations

Question 23

State a medical and an industrial use of x-rays

Answer 23

Medical - dental x-rays
Industrial - airport security scans

Question 24

State a medical and an industrial use of gamma rays

Answer 24

Medical - radiotherapy
Industrial - Detecting pipeline leaks

Question 25

What are the two equations we might use for this topic?

Answer 25

d = vt and v = f x lambda

Question 26

A radiowave is sent out, reflects off a mirror 40 m away, then returns to the original point. How would you calculate the time taken to travel from emission to return?

Answer 26

DOUBLE THE DISTANCE d = v x t so 40 = 3x10^-8 ms^-1 x t