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0.5. which is better fuel- Coke or coal?
0.8. Which property of petroleum is used for separating it into various fractions?
0.7- What are the species existing in small numbers called?
0.8- What is the height of mercury column in a simple barometer at the sea level?
0.9. The moving parts of a machine will become hotter or less hot if they are lubricated?
010- Do all vibrating bodies produce similar sound?
Answers
Coal and coke both are as fuels. But, coke is considered to be a better fuel than coal because of the following reasons: (i) Coke has been higher calorific value than coal: So, coke produces more heseparating it into various fractions?
2)Crude oil is separated into fractions by fractional distillation. The fractions at the top of the fractionating column have lower boiling points than the fractions at the bottom. All of the fractions are processed further in other refining units.
3)They are known as extinct species. Hope it will help you
4)76 cm
Hence, The vertical height of mercury which a simple barometer can support at sea level is less than 76 cm.
5)friction causes heat. it becomes less hot as the lubricants reduce friction.
6)Sound is produced by vibration of any object in a medium. If the vibration is enough for human and the vibration is in a medium , it will produce sound. If the vibrating bodies are in space , they will not produce sound
Answer:
5. Coke is a better fuel because coke produces more heat on burning as compared to coal. Coke has higher calorific value than coal. When equal masses of coke and coal are burnt, coke produces more heat. Also when coke is burnt, smoke is not obtained whereas coal produces smoke.
6. Crude oil is separated into fractions by fractional distillation. The fractions at the top of the fractionating column have lower boiling points than the fractions at the bottom. All of the fractions are processed further in other refining units.
7. Species that at present exist in small numbers are called endangered species.
8. At sea level, the atmosphere will push down on a pool of mercury and make it rise up in a tube to a height of approximately 760mm (roughly 30in). We call this air pressure one atmosphere (1 atm).
9. It will become less hot as lubricants decreases friction and ensures smooth working of machines.
10. No. For example take a piano, a vibrating body it produce a different sound and take a drum it is also a vibrating body but it produce different sound from piano .