B.) 621,780 kilograms limit of an imported good (is correct on grad point )
Answer:
Statement that is true about electromagnetic and mechanical waves is:
Option B: Mechanical waves must travel through a medium, but electromagnetic waves do not require a medium to travel.
Explanation:
'Electromagnetic' waves do not need any medium to travel whereas 'mechanical waves' need a medium or matter for transmission. Electromagnetic waves are produced by the 'vibrations' of the charged particles. They can even travel in vacuum.
On the contrary, mechanical waves are caused by the 'wave amplitude'. Mechanical wave can travel in solid, liquid and gas and are considered to be periodic disturbance.
Thus, Option B is the most statement apt explaining the difference between electromagnetic and mechanical waves.
