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Telecomunication
Question | Answer |
---|---|
what is the speed of sound through air? | 340m/s |
What is the speed of light through air? | 3,000,000,000 |
give an example where light and sound can be seen and heard at different moments. | when lightning flashes |
give the formula for measuring the speed of an object when you have the distance and the time. | S=D/T |
what is the amplitude of a wave? | the size of maximum disturbance from the center position. |
What is the crest? | It is the peak point of the amplitude |
Explain what the wave length is. | It is the distance from one point on a wave to the next point on the next wave. |
What is meant by the frequency? | the number of waves passing a point in one second. |
Define the wave speed. | Distance traveled by a wave in one second. |
How do you find the frequency of a wave if you are given the wave length and the speed? | F=v/lamda |
What is a transmitter? | a tool hat sends out signals |
Name the purpose of a receiver. | it receives signals. |
what is the angle of incidence? | the angle of the light signal by the normal. |
Name 3 advantages of optical fibers. | Cheaper, smaller, lighter, greater signal capacity, higher signal quality, ect not faster! |
How do optical fibers work? why? | they work by using total internal reflection. this means that the angle of incidence is large meaning it reflects along the fiber without penetrating the fiber and escaping. |
list the main components of a receiver. | Aerial, tuner, decoder, amplifier loudspeaker. |
What is an amplitude modulated wave (AM)? | it is used as a signal and is a combination of a carrier wave and an audio signal. |
Explain how a picture tube works. | The picture tube contains an electron gun which fires electrons at a phosphor coated screen. the electron gun fires electrons at the screen where the kinetic energy of the electrons is turned into a spot of light. |