EM Waves

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SPEED TEST
















Some Observations

• EM wave travels at the "speed of light", please understand that visible light itself is contained within the EM spectrum. It is more appropriate to state 3.0 x 10^8 m/s in vacuum.

• Q3, most of you understand that when frequency reduce, wavelength will increase, however they are not in a linear relationship. and the graph (graph a) should not touch x and y axis.

• Students like to write shortest "frequency" and longest "frequency" which is inappropriate, use lower or higher instead.
  
  1001
  
  
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Light

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SPEED TEST

1001


TYS


ASSIGNMENT


WORKBOOK

Sound

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SPEED TEST
1. D
The is no medium in outer space for sound to travel
2. B
The particles inside a solid are closely packed, thus allowing the transfer of vibrational energy to be faster.
3. C
Human’s audible range is 20 Hz to 20kHz.
4 . B
Satellite does not communicate using sound waves
5 B
Time to travel across room = 0.060 s / 2 = 0.030 s
Distance = 330 x 0.030 = 9.9 m
6. C
Increase frequency of teeth hitting card to increase pitch
7. C
Higher pitch implies higher frequency , more waves generated per second
8. B
Reflected wave has the same wavelength but different velocity due to the change in direction. The amplitude will be lower.
9. A
All electromagnetic waves are transverse wave
10. B
1^st echo = (330 m x 2) / 330 ms^-1 = 2.0 s
2^nd echo = (660 m x 2) / 330 ms^-1 = 4.0 s
Therefore time interval is 2.0 s

1001


TYS


ASSIGNMENT


WORKBOOK

Electrostatic

If you have any questions please post accordingly...

SPEED TEST
1. D
The Styrofoam balls will be charged with the same charges as the rod and each other
2. B
Only negative charges can move
3. B
A: electric
C: magnetic
D: magnetic
4. A
An earthed object will allow excess charges to flow away to earth and leave the object uncharged.
5. C
R: charges in the sphere that has the same charges as those in the rod are repelled away from the rod.
P: the repelled charged flows away from the sphere through the earth link.
Q: no more charges can flow to or from the sphere
S: the charges in the sphere are spread evenly
6. B
Field lines of like charges will push away from each other.
7. C
Like charges repel

1001


TYS


ASSIGNMENT


WORKBOOK