true or false The Doppler effect is a change in frequency due to the relative motion of a source of sound. 27. The amplitude of the wave is the time it takes it to pass a point. 28. When light passes through a lens it bends due to the property called refraction. 29. A magnifying glass when used to enlarge letters on a page is producing a virtual image. 30. The normal hearing range is between 20 hz and 80,000 hz Solution 1) doppelr effect is true 2) amplitude is the displacement of the particle from the mean position false 3) refraction means bending nature of light it is true 4) true magnifying lens is used to see the smaller objects to larger objects 5) normal hearing range is 20 to 20000 Hz false .

1. true or false
The Doppler effect is a change in frequency due to the relative motion of a source of sound.
27. The amplitude of the wave is the time it takes it to pass a point.
28. When light passes through a lens it bends due to the property called refraction.
29. A magnifying glass when used to enlarge letters on a page is producing a virtual image.
30. The normal hearing range is between 20 hz and 80,000 hz
Solution
1) doppelr effect is true
2) amplitude is the displacement of the particle from the mean position
false
3) refraction means bending nature of light it is true
4) true
magnifying lens is used to see the smaller objects to larger objects
5) normal hearing range is 20 to 20000 Hz
false