CBSE Class 10 Science 2017 · Paper 531 · Question 18

(i) Two arguments (any two of these): (1) Idling engines release poisonous gases, such as carbon monoxide and oxides of nitrogen and sulphur, together with smoke; at a crowded crossing these cause breathing trouble and illness among the people nearby, as Saumya experienced. (2) An idling engine burns petrol or diesel without moving the vehicle; these come from petroleum, a limited fossil fuel that took millions of years to form and will run out, so switching off saves fuel and money. (3) Burning less fuel also means less carbon dioxide, which adds to global warming, and fewer oxides of sulphur and nitrogen, which cause acid rain. (ii) Two ways: use public transport, share vehicles, or walk or cycle for short distances; and switch off vehicle engines at red lights, and lights, fans and other appliances when they are not needed. Using energy-efficient bulbs and solar water heaters also helps. (iii) Two values: concern for the environment (environmental awareness) and a sense of social responsibility (concern for the health of others); leadership and initiative are also shown.