Smog is essentially caused by the presence of -

1. ${\mathrm{O}}_2$, ${\text{O}}_3$

2.  ${\mathrm{O}}_{2 }$, ${\mathrm{N}}_2$

3. Oxide of N and S

4. ${\mathrm{O}}_3$, ${\mathrm{N}}_2$

Assertion(A): Both ${\mathrm{SO}}_2$ and ${\mathrm{NO}}_2$ are major components of air pollution.

Reason(R): ${\mathrm{SO}}_2$ forms reducing smog while ${\mathrm{NO}}_2$ is a component of oxidizing smog.

1. Both Assertion & Reason are true and the reason is the correct explanation of the assertion.

2. Both Assertion & Reason are true but the reason is not the correct explanation of the assertion

3. Assertion is a true statement but Reason is false.

4. Both Assertion and Reason are false statements.

Major component of acid rain is : 

1. ${\mathrm{HNO}}_3$ 

2. ${\mathrm{H}}_2{\mathrm{SO}}_4$

3. HCl

4. ${\mathrm{H}}_2{\mathrm{CO}}_3$

Ozone depletion occurs in : 

1. Tropospheric pollution.

2. Stratospheric  pollution.

3. Air pollution.

4. Photochemical smog.

The incorrect statement about carbon monoxide is-

Select the correct statement from the following statements?

‘White lung cancer’ is caused by : 

1. Asbestos

2. Silica

3. Textiles

4. Paper

Incorrect statement among the following is: 

1. Oxides of sulphur, nitrogen, and carbon are the most widespread air pollutant.

2. pH of drinking water should be between 6.5 and 8.5.

3. Concentration of dissolved oxygen below 6 ppm is good for the growth of fish.

4. Clean water would have a BOD value of less than 5 ppm.

The aromatic compound that is present as particulate among the following is : 

1. Benzene

2. Toulene

3. Nitrobenzene

4. Polycyclic hydrocarbons

A non-greenhouse gas is : 
1. CO₂
2. CH₄
3. Chlorofluorocarbons
4. O₂