Which one of the following is responsible for formation of smog? ans. automobile emissions combustion of fossil fuel nitric acid plant emissions all of the above

The answer to your question is "all of the above". Smog is formed due to a combination of various factors.

1. Automobile emissions: Cars and trucks produce a significant amount of emissions, including nitrogen oxides and volatile organic compounds, which contribute to the formation of smog.

2. Combustion of fossil fuels: Power plants and industrial facilities that burn fossil fuels like coal and oil also release large amounts of air pollutants that contribute to smog.

3. Nitric acid plant emissions: Industrial processes, such as those in nitric acid plants, can release nitrogen oxides and other pollutants that contribute to smog.

So, all these factors - automobile emissions, combustion of fossil fuels, and nitric acid plant emissions - are responsible for the formation of smog.