Answer:
Wave X has a shorter wavelength.
Explanation:
The relation between the speed of a wave, its wavelength and frequency is given by :

It can be seen that the relationship between the frequency and wavelength is inverse.
In this problem, it is mentioned that two sound waves (wave X and wave Y) are moving through a medium at the same speed. The frequency of wave X is greater than wave Y. Then it would mean that wave X have shorter wavelength than wave Y (due to inverse relation).
Answer:False
Explanation:
Work is being done on a body when it causes displacement of body on the application of force

When we pull the door by a force it causes zero displacements of the door. So we can say that work done on it is zero.
Thus the above-given statement is false
Answer:
Oligopoly
Explanation:
An oligopoly is the structure of the market that is characterized by the domination of a few firms or industries. Other small firms also operate in the same market, but the power concentration is associated with few firms only. Interdependency among the firms helps in planning and strategy making to introduce new ideas to increase the market activities. The competition in the market is reduced when a few of the firms dominate the market. It results in an increase in the price of commodities.
Answer:A compound is a substance formed when two or more elements are chemically joined.
Explation:Water, salt, and sugar are examples of compounds.
I hope this helps<3