Q1. The Supersonic jets tend to cause
(a) Destruction of ozone layer
(b) Sound pollution
(c) Nervous system breakdown
(d) All of the above
(UPSC Prelims 1979)
Answer: (a) Destruction of ozone layer
Explanation: Supersonic jets, flying at high altitudes, release nitrogen oxides that can deplete the ozone layer. Though they also contribute to noise pollution, their environmental impact on the stratosphere is a major concern.
Q2. Ozone present in the ozone layer of the atmosphere is important because
(a) It gives oxygen on dissociation
(b) It shields other gases
(c) It helps in the growth of the plants by absorbing a large proportion of the sun’s ultraviolet radiations
(d) None of these
(UPSC Prelims 1982)
Answer: (c)
Explanation: The ozone layer absorbs harmful ultraviolet (UV) radiation from the Sun, protecting living organisms from DNA damage and skin diseases. This shielding effect is vital for ecological balance.
Q3. Which of the following statements about ozone layer is correct ?
(a) It converts UV radiations into electrical energy
(b) It protects the earth’s life forms by preventing the damaging UV radiations from reaching earth’s surface
(c) It is of uniform thickness
(d) None of the above
(UPSC Prelims 1986)
Answer: (b) It protects the earth’s life forms by preventing the damaging UV radiations from reaching earth’s surface
Explanation: The ozone layer absorbs harmful ultraviolet (UV) radiation from the sun, thereby protecting living organisms on Earth. It is not of uniform thickness, and it does not convert UV into electrical energy.
Q4. Ozone layer of atmosphere absorbs
(a) Ultraviolet rays
(b) Infrared rays
(c) All radiations of light
(d) Cosmic rays
(UPSC Prelims 1987)
Answer: (a) Ultraviolet rays
Explanation: The ozone layer in the stratosphere acts as a protective shield by absorbing harmful ultraviolet (UV) rays from the sun. This prevents excessive UV radiation from reaching Earth’s surface, which can cause skin cancer and damage ecosystems.