Description : We feel cool when we sit near the fan, this is because – (1) fan gives cool air. (2) an cools surrounding air. (3) air vapourises the sweat on our body. (4) we feel cool when air touches the body.
Last Answer : (3) air vapourises the sweat on our body. Explanation: We feel comfortable sitting under a fan when we are perspiring because a fan increases the rate of evaporation of sweat (or moisture) from our body and makes us feel cool and comfortable.
Description : We feel cool when we sit near the fan, this is because (1) fan gives cool air. (2) fan cools surrounding air. (3) air vapourises the sweat on our body. (4) we feel cool when air touches the body.
Last Answer : air vapourises the sweat on our body.
Description : The freezer in a refrigerator is fitted near the top (a) to keep it away from the hot compressor which is near the bottom (b) because of convenience (c) so that it can cool the whole interior by setting up convection currents (d) without any specific purpose
Last Answer : Ans:(c)
Description : The surface of water in a pond remains cool even on a hot day because 1. water evaporates at the surface and evaporation causes cooling 2. the heat absorbed at the surface is transmitted downwards 3. Water in contact with the bottom ... /are correct? (a) 1 only (b) 3 only (c) 1 and 3 (d) 1, 2 and 3
Last Answer : Ans:(a)
Description : One feels cold after a dip in sea water due to (a) convection currents (b) the deposition of salt on the body (c) the evaporation of water on the body (d) the difference in temperatures between land and sea
Description : The water in an open pond remains cool even in hot summer because (a) Of continuous evaporation of water (b) Water radiates heat more rapidly than the atmosphere (c) Water absorbs heat less rapidly than the atmosphere (d) Water absorbs heat more rapidly than the atmosphere
Description : During hot weather, the fan produces a feeling of comfort. This is because – (1) fan supplies cool air (2) fan cools the air (3) our perspiration evaporates rapidly (4) conductivity of air increases
Last Answer : (3) our perspiration evaporates rapidly Explanation: Fans make the air more comfortable for two reasons: (1) by moving the air, they blow away body heat and evaporate sweat, cooling the body, and (2) they also mix the cooler air near the floor with the warmer air by people's faces.
Description : During hot weather, the fan produces a feeling of comfort. This is because (1) fan supplies cool air (2) fan cools the air (3) our perspiration eva-porates rapidly (4) conductivity of air increases
Last Answer : our perspiration eva-porates rapidly
Description : The freezer in a refrigerator is fitted near the top – (1) to keep it away from hot compressor which is nearer to the bottom (2) because of convenience (3) it facilitates convection currents (4) to minimise power consumption
Last Answer : (3) it facilitates convection currents Explanation: The freezer in a refrigerator is fitted near the top so that it can cool the whole interior by setting up ... compartment temperature excessively causes difficulties in maintaining above-reezing temperature in the refrigerator compartment.
Description : The freezer in a refrigerator is fitted near the top (1) to keep it away from hot compressor which is nearer to the bottom (2) because of convenience (3) it facilitates convection currents (4) to minimise power consumption
Last Answer : it facilitates convection currents
Description : The twinkling of stars can be partly attributed to (a) intermittent shining (b) convection currents in the atmosphere (c) atmospheric refraction (d) the unstable motion of the earth
Description : Light coloured clothes are preferred in summer because (a) light colours are good radiators of heat (b) light colours are poor absorbers of heat (c) they soak sweat faster (d) they allow body heat to escape faster
Last Answer : Ans:(b)
Description : You might want to play with this pet, if you can't sleep at night. With its thin metal skin, it is a welcome sight. Many people wish to hear this animal's hiss. When they are away, it is something ... will throw it in the waste. And in your haste. Might get another one. What is this pet? -Riddles
Last Answer : A can of beer.
Description : A coal with high ash content is undesirable, as (A) It is abrasive to the coal pulveriser (i.e. ball mill) and the combustion chamber (B) The ash in molten condition gets absorbed in the pores of the ... and stick to the boiler tubes thereby reducing the heat transfer (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Pick out the wrong statement pertaining to 'green house' for the plants. (A) 'Green house' (made of glass) allows visible sunlight (i.e., short wavelength solar radiation like ultra-violet rays) ... ' thereby warming up the earth's surface (D) 'Green house' is colder than the outside atmosphere
Last Answer : (D) 'Green house' is colder than the outside atmosphere
Description : ____ heating means that the circulation of currents in one region inside a can distributes the heat to another. a. Conduction c. Convection b. Radiation d. Slow
Last Answer : c. Convection
Description : By which of the following methods could a cup of hot coffee lose heat if placed on a metal table in a room? (a) Conduction and radiation (b) Conduction and convection (c) Convection and radiation (d) Conduction, convection, radiation and evaporation
Last Answer : Ans:(d)
Description : Which of the following are methods of heat transfer? (1) Convection (2) Evaporation (3) Revolution (4) Thermal Expansion
Last Answer : (1) Convection Explanation: Convection is the transfer of heat from one place to another by the movement of fluids. It is usually the dominant form of heat transfer (convection) in liquids and ... the combined processes of conduction (heat diffusion) and advection (heat transfer by bulk fluid flow).
Description : Pick out the wrong statement. (A) In case of heat transfer by purely forced convection, GR /Re 2 ≤ 1 (B) The equivalent diameter of heat transfer for a duct of ... nucleate boiling depends basically on the ease with which the bubbles are formed and detached from the heating surface
Last Answer : (B) The equivalent diameter of heat transfer for a duct of square crosssection (having each side as 'x') is equal to 4x
Last Answer : Convection
Description : The difference in air temperature over land compared to over water causes convection currents in the atmosphere. How would a person at the beach experience these convection currents?
Last Answer : dats gay
Description : Water is a highly effective coolant for a car engine because -----? A. Water is good conductor of heat B. Water has very high specific heat capacity (Answer) C. Water boils at a comparatively high temperature D. Evaporation of water produces lot of cooling
Last Answer : B. Water has very high specific heat capacity (Answer)
Description : Water is a highly effective coolant for a car engine because _____ A. Water is good conductor of heat B. Water has very high specific heat capacity C. Water boils at a comparatively high temperature D. Evaporation of water produces lot of cooling
Last Answer : ANSWER: A
Description : Only small amount of evaporation of water produces large cooling effects because of its (A) Large latent heat (B) Low viscosity (C) Small latent heat (D) None of these
Last Answer : (A) Large latent heat
Description : Extensive deserts occur in the western tropical regions of continents because : (1) of easterly trade winds. (2) cold ocean currents flow along the western coasts. (3) of the effect of both the ... winds and cold ocean currents. (4) the rate of evaporation is greater along the western margin areas.
Last Answer : (3) of the effect of both the off-shore easterly trade winds and cold ocean currents. Explanation: Extensive deserts occur in the western tropical regions of continents because of the effect of ... is found near the tropics of Cancer and Capricorn, usually toward the western side of the continents
Last Answer : of the effect of both the offshore easterly trade winds and cold ocean currents.
Description : reduction in thermal resistance during heat transfer does not occur in the (A) Convection heat transfer by stirring the fluid and cleaning the heating surface (B) Conduction heat transfer by ... Radiation heat transfer by increasing the temperature and reducing the emissivity (D) None of these
Last Answer : Option C
Description : What is transported when warm ocean currents cool as they flow along the coastline away from the equator?
Last Answer : Water
Description : Imagine that a 20 mile diameter hole is bored along the diameter of the Earth extending from the North Pole to the South Pole, that all air and gases are pumped out of this hole, and that the temperature ... between the loci of the hole with the opposite surfaces of the Earth. z) none of the above.
Last Answer : ANSWER: Y -- FOREVER OSCILLATE IN SIMPLE HARMONIC MOTION ALONG THE OLE
Description : Woollens keep us warm in winter because they (a) produce more warmth (b) are good absorbers of heat (c) do not allow our body heat to escape (d) do not allow cool air to enter
Description : Once every year a farmer walks about on his farm property, picks out his favorite tree, and chops it down with an axe. He then drags the tree home and puts it in a metal bowl. The farmer ... a crisp. How can you explain this apparent drastic change in the farmer's mood toward this tree? -Riddles
Last Answer : The man owns a Christmas tree farm where he grows thousands of Christmas trees for sale to the public. He is simply performing his annual Christmas ritual of selecting a tree, placing it in a tree stand, keeping it healthy for two weeks, and then disposing of it.
Description : For the air water system under ambient conditions, the adiabatic saturation temperature and the wet bulb temperature are nearly equal, because (A) Water has a high latent heat of evaporation (B) Lewis number is close to unity (C) They are always equal under all circumstances
Last Answer : (A) Water has a high latent heat of evaporation
Description : lass Ionomer Cement sets because of,** A. Acid-Base reaction B. Addition polymerisation reaction C. Growth of glass crystals D. Slip plane locking E. Solvent evaporation
Last Answer : A. Acid-Base reaction
Description : Is a celling fan forcing the warm air downword convection?
Last Answer : Need answer
Description : During the constant rate period of drying of a solid, (A) Increased air humidity decreases the rate of drying (B) Increasing the air temperature decreases the drying rate (C) Surface evaporation of unbound moisture occurs (D) None of these
Last Answer : (C) Surface evaporation of unbound moisture occurs
Description : Pick out the wrong statement. (A) In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2 (B) Sherwood number in mass transfer corresponds to ... tube heat exchangers. At higher pressure, however, it is customary to put gas in the tube side
Last Answer : (C) Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt number is larger
Description : Addition of plasticisers to polymers results in partial neutralisation of intermolecular forces of attraction between the macro-molecules thereby increasing its (A) Tensile strength (B) Chemical resistance (C) Flexibility (D) All (A), (B) & (C)
Last Answer : (C) Flexibility
Description : Vasoactive drugs which cause the arteries and veins to dilate, thereby shunting much of the intravascular volume to the periphery and causing a reduction in preload and afterload include agents ... Furosemide (Lasix) Furosemide (Lasix) is a loop diuretic that reduces intravascular fluid volume.
Last Answer : a) Sodium nitroprusside (Nipride) Sodium nitroprusside is used in the treatment of cardiogenic shock.
Description : Which one of the following statements regarding a catalyst is not correct? A An enzyme is a catalyst that only binds certain substrates. B An enzyme is a protein that is a highly ... increasing the activation energy. D Catalysts do not alter the equilibrium constant for a chemical reaction.
Last Answer : C Catalysts increase the rate of a reaction by altering the mechanism, thereby increasing the activation energy.
Description : Which one of the following statements is correct with respect to kidney function regulation? (a) When someone drinks lot of water, ADH release is suppressed. (b) Exposure to cold temperature ... During summer when body loses lot of water by evaporation, the release of ADH is suppressed.
Last Answer : (a) When someone drinks lot of water, ADH release is suppressed.
Description : Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in – (1) Conduction (2) Convection (3) Radiation (4) Both conduction and convection
Last Answer : (2) Convection Explanation: The process of heat transfer from one place to an-other place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the ... heated particles of the substance. The fluids (liquids and gases) are heated by this process.
Description : Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in - (1) Conduction (2) Convection (3) Radiation (4) Both conduction and convection
Last Answer : (2) Convection Explanation: The process of heat transfer from one place to another place without the movement of particles is called conduction,
Description : Fluid motion in the natural convection heat transfer between a solid surface and a fluid in contact with it, results from the (A) Existence of thermal boundary layer (B) Temperature gradient produced ... difference (C) Buoyancy of the bubbles produced at active nucleation site (D) None of these
Last Answer : (D) None of these
Description : Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in (1) Conduction (2) Convection (3) Radiation (4) Both conduction and convection
Description : Crude oil is subjected to vacuum distillation in the last stage, because (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose (B) Lighter/low ... prone to thermal decomposition (C) High purity products can be obtained thereby (D) None of these
Last Answer : (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose
Description : Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its (A) Emissivity factor is higher (B) Sulphur content is lower (C) Flue gas has lower dew point thereby facilitating more waste heat recovery (D) All (A), (B) and (C)
Description : Why is induced draught considered better than the forced draught? a) Because power requirement is high for forced draught b) Maintenance of induced draught fan is costlier c) Forced draught is less efficient d) Forced draught produces less amount of speed of air
Last Answer : Because power requirement is high for forced draught
Description : In which part of earths core do convection currents occur?
Description : How does the sun drive convection currents in the ocean and in the atmosphere?
Last Answer : By heating some places more than others.