Download Consolodation on the electromagnetic spectrum

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The Electromagnetic Spectrum
Consolidation questions
1. Write in the correct word:
Waves transfer _________________ from one place to another.
2. Correctly label the wavelength and amplitude on the following diagrams:
3. a) The top image in question 1 is emitted in 1 second. What is the frequency?
b) If these waves were now emitted in half a second, what is the new frequency?
4. Fill in the correct word: parallel/perpendicular
a) In transverse waves, the direction of the wave is ___________________________
to the direction of oscillation.
b) In longitudinal waves, the direction of the wave is __________________________
to the direction of oscillation.
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The equation that relates speed, wavelength and frequency of a wave is: v = λ x f
5. A GPS satellite sends a pulse to Earth, of wavelength 0.19 m. What is the frequency
of the pulse? [speed of light in vacuum and air = 3 x 108 m/s]
6. a) A hummingbird beats its wings 1,500 times per minute. What is the frequency in
Hertz of the sound wave this will produce?
b) What is the wavelength of the wave? [speed of sound in air = 340 m/s]
7. a) Deri and Elise stand 4m apart and hold a stretched slinky between them. Deri
sends a single wave along the slinky. It takes 2 seconds for the wave to travel to Elise.
What is the wave speed?
b) Deri can create 2 waves like this every second. What is the wavelength of the
wave?
8. a) A laser gives out blue light at a frequency of 650 Tera Hz (650 x 1012 Hz). What is
the wavelength of this light in air? [speed of light in air = 3 x 108 m/s]
b) The laser light enters a glass prism. The speed of light in glass is two thirds the
speed of light in air. What is the new speed of the blue light?
c) The frequency of the blue light in the prism is unchanged. What is the new
wavelength?
9. Draw on the correct reflected rays:
mirror
r
rro
mi
mirror
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10. Draw the correct refracted rays:
air
air
glass
glass
11. Identify what the following pictures are showing: (either reflection, refraction,
diffraction or dispersion)
A
D
G
B
C
E
F
H
I
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12.Write out the electromagnetic spectrum in order of wavelength, starting with the
longest:
__________________________________
__________________________________
__________________________________
Visible light
__________________________________
__________________________________
__________________________________
13.Which three EM waves are dangerous to humans?
14. Which EM wave...
a) ...is used to transfer information through optical fibres?
b) ...is used to broadcast information around the globe?
c) ...is used to transmit information to satellites and mobile phone networks?
d) ...has the highest frequency?
e) ...is used to observe the universe at Jodrell Bank?
Jodrell Bank Discovery Centre
www.jodrellbank.net
The Electromagnetic Spectrum
Answers
1. Waves transfer energy from one place to another
2. Wavelength must go from any point on the wave, to the same point on the next wave (e.g. peak-topeak or trough-to-trough). The horizontal arrows show this.
Amplitude goes from the midpoint of the wave, to the maximum height (or lowest point) of the
wave. The vertical arrows show this.
3. Frequency (in Hertz) is the number of whole waves emitted per second.
a) 2.5 Hz
b) 5 Hz
4. a) In transverse waves, the direction of the wave is perpendicular to the direction of oscillation.
b) In longitudinal waves, the direction of the wave is parallel to the direction of oscillation.
5. 1.58 x 109 Hz (1.58 GHz)
6. a) 1.5 x 103 Hz (1.5 kHz)
7. a) 2 m/s
b) 0.22 m (22 cm)
b) 1 m
8. a) 4.6 x 10-7 m (460 nm)
b) 2 x 108 m/s c) 3.1 x 10-7 m (310 nm)
9. Angle of reflection = angle of incidence
mirror
r
rro
mi
mirror
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10. When waves slow, they bend towards the normal.
Refraction does not occur when incoming waves are perpendicular.
air
air
normal
normal
glass
glass
11.
a) refraction
b) diffraction
c) dispersion
d) reflection
f) diffraction
g) dispersion
h) refraction
i) refraction
e) reflection
12. Radio, Microwave, Infrared, Visible light, Ultraviolet, X-ray, Gamma ray
13. Ultraviolet, X-ray, Gamma ray
14.
a) Visible light is used to transfer information through optical fibres.
b) Radio waves are used to broadcast information around the globe.
c) Microwaves are used to transmit information to satellites and mobile phone networks.
d) Gamma rays have the highest frequency.
e) Radio waves are used to observe the universe at Jodrell Bank.