Answer:
Step-by-step explanation:
1 ) False . The reason given in the problem is wrong .
2 ) When a source of sound approaches an observer , the frequency of the sound appears of having higher frequency . When it goes away from the observer , its sound appears of having lower frequency . This is due to the phenomenon of Doppler's effect .
3 ) The statement is false.
Doppler shift is a phenomenon which is found in light also . The frequency of light from distant stars coming towards the earth appears to have blue sift signalling increasing frequency . It is similar to doppler shift in sound.
4 ) The statement is true . When the source of sound approaches an observer , its intensity appears to increase due to apparent increase in the frequency due to Doppler's shift.