Description : When the humidity ratio of air increases the air is said to be A. dehumidified B. humidified C. heated D. cooled
Last Answer : ANSWER : B
Description : In sensible cooling process the relative humidity: A. decreases B. increases C. remains constant D. none of the above
Description : Air can be cooled and dehumidified by A. circulating chilled water in tube across air flow B. placing evaporator coil across air flow C. spraying chilled water to air D. all of the mentioned
Last Answer : ANSWER : D
Description : Work input to the air compressor with n as index of compression A. Increases with increase in value of n B. Decrease with increase in value of n C. remains same whatever the value of n D. first increase and then decreases with increase of value of n.
Last Answer : ANSWER : A
Description : In sensible heating or cooling, A. work done remains constant B. dry bulb temperature or air remains constant C. both of the mentioned D. none of the mentioned
Description : With increase in absolute humidity, the dew point of an unsaturated mixture of air and water vapor (at constant pressure and temperature). (A) Increases (B) Remains unchanged (C) Decreases (D) Decreases linearly
Last Answer : (A) Increases
Description : Absolute humidity in air (A) Decreases at higher altitudes (B) Increases at higher altitudes (C) Remains constant at all altitudes (D) None of these
Last Answer : Answer: Option A
Description : On a day when the partial pressure of water vapor remains constant, what happens as the temperature rises? a. the relative humidity increases b. the relative humidity decreases c. the relative humidity remains constant d. the air would eventually become saturated
Last Answer : the relative humidity decreases
Description : Under-cooling in a refrigeration cycle (a) increases COP (b) decreases COF (c) COP remains unaltered (d) other factors decide COP
Last Answer : Ans: a
Description : Superheating in a refrigeration cycle (a) increases COP (b) decreases COP (c) COP remains unaltered (d) other factors decide COP
Last Answer : Ans: b
Description : At lower temperatures and pressures, the latent heat of vaporization of a refrigerant (a) decreases (b) increases (c) remains same (d) depends on other factors
Description : In a simple carburetor, the air-fuel ratio increases when the A. density of air increases B. velocity of air increases C. velocity of air decreases D. density of air decreases
Description : Which one of the following statement is not correct for the volumetric efficiency of a reciprocating air compressor? A. It decreases with increase in ambient temperature B. It increases with ... It increases with decrease in clearance ratio D. It decreases with increases in delivery pressure
Description : Which one of the following statements are correct for reciprocating air compressor? A. Its volumetric efficiency increases with increasing clearance ratio B. Its volumetric efficiency increases ... ratio D. Its volumetric efficiency decreases with increasing clearance ratio and pressure ratio
Description : If the temperature of a piece increases suddenly, the relative humidity– (1) increases (2) decreases (3) remains constant (4) fluctuates
Last Answer : (2) decreases Explanation: Relative humidity is the ratio of the partial pressure of water vapour in a airwater mixture to the saturated vapour pressure of water at a specific temperature.
Description : If the temperature of a place increases suddenly, the relative humidity – (1) Increases (2) Decreases (3) Remains constant (4) Fluctuates
Last Answer : (2) Decreases Explanation: Relative humidity is the ratio of the partial pressure of water vapor in an airwater mixture to the saturated vapor pressure of water at a prescribed ... of the system decreases because the saturated vapor pressure of water increases with increasing temperature.
Description : If the temperature of a place increases suddenly, the relative humidity (1) Increases (2) Decreases (3) Remains constant (4) Fluctuates
Last Answer : Decreases
Description : What is the specific humidity? A. the ratio of the mass of water vapour to the mass of the total mixture of air and water vapour B. the ratio of the mass of dry air to the mass of the total mixture ... ratio of the mass of water vapour to the mass of dry air in a mixture of air and water vapour
Description : Relative humidity is a) the ratio of water vapour in the air compared to the total amount water vapour the air could contain at a given temperature b) equal to the dry bulb temperature divided by the wet bulb ... of dry air e) the ratio of the mass of water vapour divided by the mass of wet air
Description : Absolute or specific humidity is a) the actual mass of moisture present in a specific amount of air b) the maximum mass of moisture that a specific amount of air can hold c) the ratio of ... a specific amount of air at that absolute temperature e) a specific amount of air saturated with moisture
Description : Unsaturated air (with dry bulb temperature and dew point being 35°C and 18°C respectively) is passed through a water spray chamber maintained at 15°C. The air will be cooled (A) And ... (C) At the same relative humidity (D) And dehumidified with decrease in wet bulb temperature
Last Answer : (D) And dehumidified with decrease in wet bulb temperature
Description : If the temperature of intake air in internal combustion engine is lowered, the efficiency will a. increase b. decrease c. remains same d. increases upto certain limit and then decrease
Last Answer : ANSWER a. increase
Description : If the intake air temperature of Internal combustion engine increases, its efficiency will a. increase b. decrease c.remains same d unpredictable
Last Answer : ANSWER b. decrease
Description : Volumetric efficiency of a compressor without clearance volume A. Increases with increase in compression ratio B. Decreases wit increase in compression ratio C. Not dependent upon compression ratio D. Unpredictable
Last Answer : ANSWER : C
Description : How the efficiency of the SI engine is affected by the specific heat ratio (γ) of the working fluid? a. the efficiency of the engine increases with increase in specific heat ratio (γ) of the working ... not affected by change in specific heat ratio (γ) of the working fluid d. none of the above
Last Answer : ANSWER a. the efficiency of the engine increases with increase in specific heat ratio (γ) of the working fluid
Description : What is the relation between compression ratio (rk) and the efficiency of the Otto cycle? a. efficiency decreases with increase in compression ratio b. efficiency increases with increase in compression ratio c. efficiency is not affected by change in compression ratio d. none of the above
Last Answer : ANSWER b. efficiency increases with increase in compression ratio
Description : In a reciprocating air compressor the compressor work per kg of air A. Increases as clearance volume increases B. Decreases as clearance volume increases C. Is independent of clearance volume D. Increases with clearance volume only of multistage compressor
Description : When air passes through silica gel, A. it absorbs water vapour molecules B. latent heat of condensation is released C.dbt of air increases D. all of the mentioned
Description : During sensible heating of humid air (A) Relative humidity increases (B) Dew point remains constant (C) Dry bulb & wet bulb temperature increases (D) Both 'b' & 'c'
Last Answer : (D) Both 'b' & 'c'
Description : The ratio of partial pressure of water vapour in a mixture to the saturation pressure of water at the same temperature of the mixture is called as A. humidity B. partial humidity C. specific humidity D. relative humidity
Description : What is the degree of saturation? A. the ratio of the actual relative humidity to the saturated specific humidity at the same temperature B. the ratio of the actual specific humidity to the ... specific humidity to the actual specific humidity at the same temperature D. none of the above
Description : When gas changes to liquid through the process of condensation, the temperature A] Increases. B] Decreases C] Remains constant. D] None of the mentioned
Last Answer : C] Remains constant.
Description : The power required to drive a turbo compressor for a given pressure ratio decreases when A. Air is heated at entry B. Air is cooled at entry C. Air is cooled at exit D. Air is heated at exit
Description : In adiabatic evaporative cooling, heat transfer between chamber and surroundings is ____ A. zero B. high C. low D. none of the mentioned
Description : When an unsaturated air-water mixture is heated at constant pressure, then (A) The partial pressure of water vapour increases (B) The specific humidity decreases (C) The relative humidity increases (D) The relative humidity decreases
Last Answer : D) The relative humidity decreases
Description : What is the relative humidity for a saturated air? A. 0% B. 50% C. 100% D. cannot say
Description : Wet-bulb temperature is: a. The temperature indicated by a thermometer whose bulb covered by a water-wetted wick and exposed to a rapidly moving stream of air b. The same as the dry-bulb ... point temperature d. Always less than the dry-bulb temperature e. Not required to find the relative humidity
Last Answer : Answer: A
Description : Dry-bulb temperature is: a. The absolute temperature corresponding to the atmospheric pressure b. The same as the wet-bulb temperature if the relative humidity is less than 100% c. Not required ... d. The temperature of the air measured with an ordinary thermometer e. The dew point temperature
Last Answer : Answer: D
Description : The term "relative humidity" applies to a) the percentage of moisture in the air as compared to the amount of moisture the air can hold at a specific temperature b) the weight of the moisture in the air c) ... of the air d) the amount of moisture in the air e) the amount of humidity in the air
Description : The heat content of air is called the _____ of the air. a. Temperature b. Humidity c. Enthalpy d. Psychrometry e. Entropy
Description : When the rate of evaporation of water is zero, the relative humidity of the air is A. 0% B. 100% C. 50% D. unpredictable
Description : When the dew point temperature is equal to the air temperature then the relative humidity is A. 0% B. 50% C. 100% D. unpredictable
Description : Adiabatic compression is one in which A. Temperature during compression remains constant B. No heat leaves or enters the compressor cylinder during compression C. Temperature rise follows a linear relationship D. Work done is maximum.
Description : The knocking tendency in CI engines increases with (a) Increase of coolant water temperature (b) Increase of temperature of inlet air (c) Decrease of compression ratio (d) Increase of compression ratio
Last Answer : Ans :c
Description : In a refrigeration cycle, the super heating……..C.O.P (a)decreases (b)does not change (c) increases (d)none of the above
Description : Formation of frost on evaporator in refrigerator (a) results in loss of heat due to poor heat transfer (b) increases heat transfer rate (c) decreases compressor power. (d) can be avoided by proper design
Description : In a battery ignition system, the intensity of spark is A. minimum at low engine speed B. minimum at low engine speed and increases with engine speed C. maximum al low engine speed and decreases with engine speed D. maximum at low engine speed
Description : The critical spark energy required to ignite a given mixture A. decreases with decreasing sparking voltage B. increases with decreasing sparking voltage C. increases with increasing sparking voltage D. decreases with increasing sparking voltage
Description : Supercharging of an IC engine is done so that the A. thermal efficiency increases B. power output increases C. speed of the engine increases D. power output decreases
Description : In `beta-` decay `n//p` ratio` :` a)May inrease or decrease b) Remains constant c)Decreases d)Increases
Last Answer : In `beta-` decay `n//p` ratio` :` a)May inrease or decrease b) Remains constant c)Decreases ... B. may increase or decrease C. increases D. decreases