i. Which is an example of a longitudinal wave?




... Answer is (a) sound wave
 In a longitudinal wave the particle displacement is parallel to the direction of wave propagation. e.g. Sound waves While, in a Transverse wave the particle displacement is perpendicular to the direction of wave propagation. e.g. Light waves, Radio waves, Water waves.


ii. How does sound travel from its source to your ear?




... Answer is (a) by changes in air pressure
A sound wave is a pressure wave; in which regions of high (compressions) and low pressure (rarefactions) are established as the result of the vibrations of the sound source.


iii. Which form of energy is sound?




... Answer is (b) mechanical
 A mechanical wave is a wave that requires a medium for their propagation and is not capable of transmitting its energy through a vacuum. So Sound waves is Mechanical because it can’t travel in vacuum.


iv. Astronauts in space need to communicate with each other by radio links because:




... Answer is (c) sound waves cannot travel in space
 Sound waves are mechanical wave that requires a medium for their propagation and is not capable of transmitting its energy through a vacuum. Therefore, astronaut uses a radio link for communication with each other.


v. The loudness of a sound is most closely related to its:




... Answer is (d) amplitude
 The loudness of sound is a phenomenon of a sound depending on the amplitude of the sound wave. It is directly proportional to the square of the amplitude of vibration. If the amplitude of the sound wave is large, then the sound is said to be loud and vice versa.


vi. For a normal person, audible frequency range for sound wave lie between:




... Answer is (b) 20 Hz and 20 kHz
Humans can detect sounds in a frequency range from about 20 Hz to 20 kHz


vii. When the frequency of a sound wave is increased, which of the following will decrease? i. Wavelength ii. Period iii. Amplitude




... Answer is (c) i. and ii. only
According to the wave formula and Frequency & Period Relation f = v / λ and f = 1 / t It is clear from the above equations that Frequency (f) varies inversely to λ and T .
 

Note:  If you are now confident to answer correctly for the above MCQs, than you can examine yourself by taking this Simple MCQS Quiz (Click here to play the Quiz)
 
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