Ans: A

Exp:

Statement-I is correct : The zone separating the troposphere from the stratosphere is known as the tropopause. The air temperature at the tropopause is about minus 80 degree Celsius over the equator and about minus 45 degree Celsius over the poles. The temperature here is nearly constant, and hence, it is called the tropopause.

Statement-II is correct : The troposphere is the lowermost layer of the atmosphere. Its average height is 13 km and extends roughly to a height of 8 km near the poles and about 18 km at the equator. The temperature in this layer decreases at the rate of 1°C for every 165m of height. Thus more heat is lost by the air while ascending towards the tropopause at the equator than at the poles. Hence, the air temperature at the tropopause over the equator is lesser than the air temperature at the tropopause over the poles.

Ans: A

Exp:

Statement 1 is correct : Carbon dioxide is an important gas as it is transparent to the incoming solar radiation but opaque to the outgoing terrestrial radiation. It absorbs a part of terrestrial radiation and reflects back some part of it towards the earth’s surface. It is largely responsible for the green house effect. The volume of other gases is constant but the volume of carbon dioxide has been rising in the past few decades mainly because of the burning of fossil fuels.

Statement 2 is incorrect : The amount of ozone gas in the atmosphere is less than Helium. The amount of gases present in the atmosphere is as given below:

Ans: D

Exp:

Statement 1 is incorrect: The earth’s surface receives most of its energy in short wavelengths. The energy received by the earth is known as incoming solar radiation (Insolation).

Statement 2 is incorrect: During its revolution around the sun, the Earth is farthest from the sun (152 million km) on 4th July. This position of the earth is called aphelion.

Statement 3 is incorrect : On 3rd January, the Earth is the nearest to the sun (147 million km). This position is called perihelion.

The solar output received at the top of the atmosphere varies slightly in a year due to the variations in the distance between the earth and the sun. The annual insolation received by the earth on 3rd January is slightly more than the amount received on 4th July. However, the effect of this variation in the solar output is masked by other factors like the distribution of land and sea and the atmospheric circulation. Hence, this variation in the solar output does not have a great effect on daily weather changes on the surface of the earth.

Ans: C

Exp:

The transfer of heat through the horizontal movement of air is called advection. The horizontal movement of the air is relatively more important than the vertical movement. In middle latitudes, most of the diurnal (day and night) variation in daily weather are caused by advection alone. In tropical regions particularly in northern India during the summer season, local winds called ‘loo’ is the outcome of the advection process. Various local winds across the world are : 

• Hot local winds
  • Foehn- Alps mountains (leeward side)
  • Chinook – Eastern Rockies mountain , USA
  • Sirocco-  Sahara desert to Mediterranean sea
• Cold local winds
  • Mistral- Alps mountain 
  • Bora – Adriatic sea
  • Buran – Siberia 

Ans: D

Exp:

The distribution of temperature across the latitudes over the surface of the earth is called its horizontal distribution. On maps, the horizontal distribution of temperature is commonly shown by Isotherms. The factors responsible for the uneven distribution of temperature are as follows:

•       Latitude
•       Land and Sea Contrast
•       Relief and Altitude
•       Ocean Currents
•       Winds
•       Vegetation Cover
•       Nature of the soil
•       Slope and Aspect