# Lightning is seen before thunder is heard because 1.Sound travels faster than light 2.The thunder has a greater distance to travel than the lightning 3.Light.

## Presentation on theme: "Lightning is seen before thunder is heard because 1.Sound travels faster than light 2.The thunder has a greater distance to travel than the lightning 3.Light."— Presentation transcript:

Lightning is seen before thunder is heard because 1.Sound travels faster than light 2.The thunder has a greater distance to travel than the lightning 3.Light travels faster than sound

A sound takes 4 s to travel 1360 m. The speed of sound is 1.0.029 m s -1 2.5440 m s -1 3.340 m s -1 4.300 000 000 m s -1

The frequency of a wave is 1.The number of waves passing in 10s 2.The time it takes 1 wave to pass a point 3.The number of waves passing in 1s 4.The time it takes 10 waves to pass a point

Wavelength is 1.The distance between a crest and trough 2.The distance between the middle of a wave and the crest 3.The distance between successive crests

Waves travelling at 10 m /s have a frequency of 4 Hz. Calculate the wavelength 1.40 m 2.2.5 cm 3.0.4 m 4.2.5 m

The mouthpiece of a telephone contains: 1.A loudspeaker that turns E S to E E 2.A microphone that turns E S to E E 3.A microphone that turns E E to E S 4.A loudspeaker that turns E E to E S

On a CRO a high frequency, loud sound would be displayed as 1.Small number of waves and big amplitude 2.Large number of waves and small amplitude 3.Small number of waves and small amplitude 4.Large number of waves and big amplitude

Fibre Optic cables are 1.Hollow cylinders of glass 2.Thick pieces of glass like string 3.Thin threads of glass

Calculate how long it takes light to travel down a fibre optic cable 20 km long 1.1.0 x 10 4 s 2.1.0 x 10 -4 s 3.4 x 10 12 s

Which part of a radio receiver separates the carrier wave from the transmitted information ? 1.Aerial 2.Tuner 3.Decoder 4.Loudspeaker

The amplifier 1.Increases the frequency of the signal and leaves the amplitude unchanged 2.Increase the amplitude and the frequency 3.Decreases the frequency and amplitude 4.Changes the amplitude but leaves the frequency unchanged

In amplitude modulation : 1.A low frequency carrier wave is added to a high frequency sound wave 2.The carrier wave frequency changes with the frequency of the sound 3.A low frequency sound wave is added to a high frequency carrier wave

Colour on a TV screen is produced by 1.Red, green and blue electrons hitting a screen 2.Electrons hitting three different colours of phosphor 3.Red, blue and green light being fired from an electron gun

White light is produced by: 1.Mixing equal intensities of red, green and blue light 2.Mixing red and blue light 3.Mixing green and blue light 4.Mixing red and green light

Radio and TV waves travel through air at 1.340 m /s 2.3 x 10 8 m/s

TV reception is more difficult in hilly areas than radio because : 1.Long wavelengths diffract less than short ones 2.Short wavelengths diffract more than long ones 3.Long wavelengths diffract more than short ones

Satellites are needed to broadcast from Dunfermline to New York because : 1.Short wavelength TV waves diffract around the earth 2.Short wavelength TV waves travel in a straight line out into space 3.Short wavelength TV waves don’t transfer enough energy

Satellite aerials need a curved reflector behind them to : 1.Gather the microwave signal over a big area and focus it 2.Gather the microwave signal over a big area and retransmit it 3.Look cool 4.Weaken the strength of the signal as it is too strong for the aerial

A geostationary satellite : 1.Is fixed in position 2.Orbits 36 000 km above the orbit and has a period of 48 hours 3.Orbits 36 000 km above the equator and has a period of 24 hours 4.Orbits 2 000 km above the equator with a period of 12 hours

The wavelength of a 9 GHz microwave signal is : 1.0.03 m 2.30 m 3.2.7 x 10 18 m

Download ppt "Lightning is seen before thunder is heard because 1.Sound travels faster than light 2.The thunder has a greater distance to travel than the lightning 3.Light."

Similar presentations