Q2) Choose the correct statement in each question. 1. A pipe carrying steam at about 300°C traverses a room, the air being still at 30°C. The major fraction of the heat loss will be by (a) conduction to the still air (b) convection to the air (c) radiation to the surroundings (d) conduction and convection put together. 2. In the cold season a person would prefer to be near a fire because (a) the conduction from the fire will be better (b) the convection will be better if he is near the fire (c) direct unimpeded radiation will provide quick warmth (d) combined conduction and convection will be better. 3. A finned tube hot water radiator with a fan blowing air over it is kept in rooms during winter. The major portion of the heat transfer from the radiator to air is due to (a) radiation (b) convection (c) conduction (d) combined conduction and radiation. 4. For a specified heat input and a given volume which material will have the smallest temperature rise (a) steel (b) aluminium (c) water (d) copper.
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A pipe carrying steam at about 300C traverses a room, the air being still at 30C. The major fraction of the heat loss will be by: Answer: (b) convection to the air Explanation: Since the air is still, conduction will not play a significant role in heat transfer. Show more…
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