Q1. Arrange the following three atmospheric layers starting from the surface of the earth :
A. Stratosphere
B. Ionosphere
C. Troposphere
(a) A, B, C
(b) C, A, B
(c) A, C, B
(d) C, B, A
(UPSC Prelims 1984)
Answer: (b) C, A, B
Explanation: The correct order from the Earth’s surface upward is:
- Troposphere (weather phenomena occur here)
- Stratosphere (contains the ozone layer)
- Ionosphere (part of the thermosphere, important for radio communication)
This sequence reflects the vertical structure of Earth’s atmosphere.
Q2. Atmospheric temperature increases at the higher altitudes due to
(a) Convection
(b) Radiation
(c) Conduction
(d) Inversion
(UPSC Prelims 1986)
Answer: (a) Convection
Explanation: Convection refers to the vertical movement of air, which can cause temperature anomalies at higher altitudes. In certain conditions, warm air rises, leading to temperature increase at elevated levels, contrary to the usual lapse rate.
Q3. Which of the following elements exists in maximum quantity in atmosphere ?
(a) Oxygen
(b) Hydrogen
(c) Carbon
(d) Nitrogen
(UPSC Prelims 1986)
Answer: (d) Nitrogen
Explanation: Nitrogen constitutes about 78% of Earth’s atmosphere, making it the most abundant element. Oxygen follows at around 21%, while carbon and hydrogen are present in trace amounts.
