Wind Energy Multiple Choice Questions on “Origin of Winds – 2”.
1. What are westerly winds?
a) Winds blowing from sub-tropical high pressure areas to sub-polar low pressure areas
b) Winds that trade with each other
c) Winds blowing from equatorial high pressure areas to sub-tropical low pressure areas
d) Winds blowing from equatorial low pressure areas to sub-tropical high pressure areas
Answer: a
Clarification: Westerly winds are winds blowing from sub-tropical high pressure areas to sub-polar low pressure areas. The direction of flow is from west to east between 30 and 60 degrees latitude.
2. Westerly winds of Southern Hemisphere ______
a) weaker and maintain a constant direction than its counterpart in Northern Hemisphere
b) are stronger and maintain a constant direction than its counterpart in Northern Hemisphere are
c) are stronger but do not maintain a constant direction than its counterpart in Northern Hemisphere
d) blow from equatorial low pressure areas to sub-tropical high pressure areas
Answer: b
Clarification: Westerly winds of Southern Hemisphere are fairly stronger and maintain a constant direction as compared to its counterpart in Northern Hemisphere. They blow from sub-tropical high pressure areas to sub-polar low pressure belts.
3. What are periodic winds?
a) Westerly winds
b) Winds that do not change their direction periodically with the change in season
c) Winds that change their direction periodically with the change in season
d) Trade winds
Answer: c
Clarification: Periodic winds are winds that change their direction periodically as the season changes. Trade and westerly winds are planetary winds and are not periodic in nature.
4. Which of the following are examples of periodic winds?
a) Gusts
b) Windstorm
c) Westerly winds
d) Monsoons, land and sea breeze, mountain and valley breeze
Answer: d
Clarification: Monsoons, land and sea breeze, mountain and valley breeze are examples of periodic winds. Westerly winds are planetary winds and are not periodic in nature. Windstorm and gusts are not periodic in nature.
5. A downburst is created by an area of rain-cooled air that _____
a) after hitting the ground generates strong winds which spread in all directions
b) don’t hit the ground
c) after hitting the ground generates extremely weak winds which spreads in all directions
d) are short gusts
Answer: a
Clarification: Downbursts are caused by an area of rain-cooled air that after hitting the ground level generates strong winds which spread in all directions. They are not gusts.
6. What is sea breeze?
a) Winds that don’t strike the ground level
b) Winds from sea that flow during day towards the land and replace the lighter and rising hot air
c) Winds that hit the land to generate extremely weak winds which spreads in all directions
d) Short gusts originating from sea
Answer: b
Clarification: When the coastal lands heat up, the air above it also gets hot. Hot air is light and rises up leading to a low pressure area. Sea breezes carry moisture from the sea and are much cooler. Thus, they rush towards the land to replace the hot air.
7. What is land breeze?
a) Winds that hit the sea to generate extremely weak winds which spreads in all directions
b) Winds from land that flow during night towards the sea and replace the lighter and rising hot air
c) Winds from sea that flow towards the land and replace the lighter and rising hot air
d) Short gusts originating from land
Answer: c
Clarification: During night, the inland temperatures drop to an extent such that the sea is warmer than the land thereby causing the air above it to become hot and rise. Cool air from land rush towards the sea to replace the hot air.
8. Which of the following equations best explains the phenomenon of winds flowing from high pressure to low pressure?
a) Pressure = Force/Area
b) Roult’s law
c) Force = mass*acceleration
d) Ideal gas equation
Answer: d
Clarification: From Kinetic theory of gases, it is evident that ideal gas equation – PV = nRT explains the phenomenon of gases flowing from high pressure to low pressure. Raoult’s law deals with vapour pressure. Force = mass*acceleration and Pressure = Force/Area do not explain kinetics of gases.
9. How do thunderstorms form?
a) Thunderstorms originate from a pleasant breeze
b) Thunderstorms are produced by mid-level clouds
c) Thunderstorms are produced by cumulonimbus cloud which generated gusty winds and heavy rains
d) Thunderstorms originate from low-level clouds and do not carry rain with them
Answer: c
Clarification: Thunderstorms is a type of storm with thunder and lightning and is produced by cumulonimbus clouds. These clouds generate strong gusty winds and heavy rains which accompany the thunderstorm.
10. Which of the following are types of winds?
a) Planetary winds, periodic winds, local winds
b) Trade winds, westerly winds, plate tectonics
c) Apples, monsoon
d) Clouds, rains, storms
Answer: a
Clarification: Planetary winds, periodic winds, local winds, trade winds, westerly winds, monsoons are types of winds. Plate tectonics is related to earth. Clouds, rains and storms are not the types of winds.
11. What is considered as a strong breeze on a Beaufort Wind Scale?
a) 0
b) 6
c) 1
d) 4
Answer: b
Clarification: Beaufort wind scale is an empirical scale for measuring wind speeds. On this scale, 0 corresponds to a calm breeze, 6 corresponds to a strong breeze, 1 corresponds to a light air and 4 corresponds to a moderate breeze.