How is a high tide caused?

Ans: The level of water in the sea changes because of the gravitational force exerted by the moon.

Water directly under the moon gets pulled towards the moon and the level of water there goes up causing high tide at that place.

why does Chennai experience an equable type of climate?

Ans: Chennai experiences an equable type of climate that is neither too hot nor too cold throughout the year due to the moderating influence of the seas.

What is Kali Baisakhi?

Ans: In West Bengal, local winds are called Kali Baisakhi which means The calamity of the month of Baisakhi.

They are also known as Norwesters because they blow in the North - West direction.

These local winds are accompanied by thunderstorms bringing in heavy rainfall. 

This rainfall is beneficial for tea crop in Assam 

And for Jute and Rice crop in West Bengal.

What effect does El-Nino have on the climate of India?

Ans: El-Nino increases the surface temperature of the sea in Central and Eastern Equatorial Pacific Ocean . In India El-Nino affects the movement of monsoon in the Indian Ocean.

What is loo?

Ans: Loo are hot dusty dry winds that blow in the month of May and June in the Northern Plains. The temperature is 45 degrees Celsius  to 50 degrees Celsius  thus causing sunstrokes .

How is rainfall caused in Punjab Haryana during winter?

Ans: During winter low pressure depressions called western disturbances originate in the Mediterranean Sea. These cyclonic wnds cross Iraq, Afghanistan and Pakistan and give rain to Northwest parts of India. This is how Punjab and Haryana gets rainfall during winter .

Why does Kodaikanal in Tamilnadu though having a high altitude does not experience snowfall?

Ans: Places in South India such as Kodaikanal in Tamilnadu even at high altitude never experience  snowfall as these places are nearer to the equator.

What are jet streams?

Ans: Jet streams are the air currents circulating in the upper layers of the atmosphere. They determine the onset and departure of the monsoons.

How can the pollution of air caused by burning coal in thermal power plants be controlled?

Pollution  in thermal power plants  can be controlled by installing electrostatic precipitators in their chimneys. As a result the unburnt carbon particles and fly-ash particles present in smoke get deposited on the inner walls of the chimney and do not go into the air. The deposited particles can be removed by sweeping the chimney from time to time.