Question

Choose the correct statement

• A. Ozone formed during photochemical smog protects us from UV radiations.
• B. Increase in tropospheric ozone can reduce food production.
• C. Photochemical smog formation is maximum in morning and evening due to heavy traffic hours.
• D. Vehicular exhaust does not contain any precursors of ozone formation in the troposphere.

Hint:

Ground-level ozone harms plants; stratospheric ozone is the shield.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Ozone is good in the stratosphere where it absorbs UV light, but harmful near the ground. Smog ozone is in the troposphere.

Step 2: Key Approach:
Check each statement against the passage and basic facts on ozone and smog.

Step 3: Check option (1).
Only stratospheric ozone shields us from UV. Ground-level ozone from smog is a pollutant that harms lungs and plants. So (1) is FALSE.

Step 4: Check option (2).
The passage says smog damages plants and crops. Ozone harms leaves and cuts photosynthesis, so crop yield falls. So (2) is TRUE.

Step 5: Check option (3).
Traffic is heavy in morning and evening, but light is weak then. Smog peaks near midday when sunlight is strongest. So (3) is FALSE.

Step 6: Check option (4).
Vehicle exhaust is rich in nitrogen oxides and hydrocarbons, the two precursors. So (4) is FALSE.

Final Answer:
Only statement (2) is correct, so the answer is option 2.
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