BOD, is

(1) Waste decomposed in 5 days

(2) Oxygen used in 5 days

(3) Microorganisms killed in 5 days

(4) Dissolved oxygen left after 5 days

Identify the wrong statement among the following.

When rain is accompanied by a thunderstorm, the pH value of the collected rain water is :

1. Dependent upon the amount of dust in the air.

2. Slightly lower when rainwater is without a thunderstorm.

3. Slightly higher when the thunderstorm is not there.

4. Unaffected by the occurrence of thunderstorms.

Depletion of which gas in the atmosphere can lead to an increased incidence of skin
cancer?

1. Ammonia

2. Methane

3. Nitrous oxide

4. Ozone

The unit for measuring ozone thickness

1. Joule

2. Kilos

3. Dobson

4. Watt

Which of the following is not one of the prime health risks associated with greater
UV radiations through the atmosphere due to depletion of stratospheric ozone?       

1. Damage to eyes
2. Increased liver cancer
3. Increased skin cancer.
4. Reduced Immune system

Which one of the following is a wrong statement? 

1. Most of the forests have been lost in tropical areas.
2. Ozone in upper part of atmosphere is harmful to animals.
3.Greenhouse effect is a natural phenomenon.
4. Eutrophication is a natural phenomenon in freshwater bodies.

Good ozone is found in the 

1. mesosphere

2.troposphere

3. stratosphere

4. ionosphere

Which country has the greatest contribution for the hole formation in ozone layer?

1. Russia

2. Japan

3. USA

4. Germany

The ‘thickness’ of Stratospheric Ozone layer is measured in/on:
1. Sieverts units
2. Dobson units
3. Melson units
4. Beaufort Scale