UPTET Paper 1 2013 Solved Paper

Concept:Greenhouse gases trap heat in the Earth's atmosphere, maintaining a warm climate. Not all gases with carbon or oxygen are greenhouse gases.Explanation:Carbon dioxide ($CO_2$), methane ($CH_4$), and nitrous oxide ($N_2O$) absorb and re-emit infrared radiation, thus acting as greenhouse gases.Carbon monoxide (CO) does not absorb infrared radiation effectively. It is mainly a poisonous gas produced by incomplete combustion of fuels.Unlike $CO_2$, CO lacks a strong ability to trap heat, so it is not considered a greenhouse gas.Therefore, among the given options, carbon monoxide (CO) is the one that is not a greenhouse gas.Answer:Option C (CO)