Description : A fuel of an octane number rating of 75 matches in knocking intensity as a mixture of a) 75% iso-octane and 25% normal heptane b) 75% normal heptane and 25% iso-octane c) 75% petrol and 25% diesel d) 75% diesel and 25% petrol
Last Answer : Answer: a Explanation: None.
Description : By supercharging the power output of an engine is expected to increase by A. 20% B. 45% C. 75% D. 50%
Last Answer : ANSWER : A
Description : In vapour compression cycle using NH3 as refrigerant, initial charge is filled at (a) suction of compressor (b) delivery of compressor (c) high pressure side close to receiver (d) low pressure side near receiver
Last Answer : Ans: c
Description : Gasohol is a mixture of a) 90% ethanol + 10% gasoline b) 10% ethanol + 90% gasoline c) 40% ethanol + 60% gasoline d) 50% ethanol + 50% gasoline
Last Answer : Answer: b Explanation: 10% ethanol + 90% gasoline makes gashol.
Description : If a dwarf pea plant was treated with gibberellic acid, it became as tall, as tall pea plants. If these pea plants are crossed with pure tall pea plants, what will be the phenotypic ratio in F1 generation? ... (b) 50% tall and 50% dwarf plants (c) 75% tall and 25% dwarf plants (d) 100% tall plants
Last Answer : Ans. ((d))
Description : 100% modulation in AM means a corresponding increase in total power by: A. 25% B. 75% C. 100% D. 50%
Last Answer : D. 50%
Description : Both husband and wife have normal vision though their fathers were colour blind. The probability of their daughter becoming colour blind is (a) 0% (b) 25% (c) 50% (d) 75%.
Last Answer : (a) 0%
Description : Albinism is known to be due to an autosomal recessive mutation. The first child of a couple with normal skin pigmentation was an albino. What is the probability that their second child will also be an albino? (a) 50% (b) 75% (c) 100% (d) 25%
Last Answer : (d) 25%
Description : Down’s syndrome is caused by an extra copy of chromosome number 21. What percentage of offspring produced by an affected mother and a normal father would be affected by this disorder? (a) 100% (b) 75% (c) 50% (d) 25%
Last Answer : (c) 50%
Description : A man whose father was colour blind marries a woman who had a colour blind mother and normal father. What percentage of male children of this couple will be colour blind? (a) 25% (b) 0% (c) 50% (d) 75%
Description : Due to the cross between TTRr × ttrr the resultant progenies show what percent of tall, red flowered plants? (a) 50% (b) 75% (c) 25% (d) 100%
Last Answer : (a) 50%
Description : In a plant, red fruit (R) is dominant over yellow fruit (r) and tallness (T) is dominant over shortness (t). If a plant with RRTt genotype is crossed with a plant that is rrtt, (a) 25% will be ... with red fruit (c) 75% will be tall with red fruit (d) all the offspring will be tall with red fruit
Last Answer : (b) 50% will be tall with red fruit
Description : tt mates with Tt. What will be characteristic of offspring? (a) 75% recessive (b) 50% recessive (c) 25% recessive (d) All dominant
Last Answer : b) 50% recessive
Description : Which of the following represents a racemic mixture? (a) 75% (R)-2-butanol, 25% (S)-2-butanol (b) 25% (R)-2-butanol, 75% (S)-2-butanol (c) 50% (R)-2-butanol, 50% (S)-2-butanol (d) none of the above
Last Answer : 50% (R)-2-butanol, 50% (S)-2-butanol
Description : Cooling efficiency of a cooling tower is significantly affected under cross-wind condition and might decrease to……… in the range of moderate to high wind velocity condition. a) 50% c) 25% b) 75% d) 90%
Last Answer : 75%
Description : For ductility consideration, the maximum percentage of steel used should not exceed ------- of the balanced steel [ A ] 25% [ B ] 50% [ C ] 60% [ D ] 75%
Last Answer : [ D ] 75%
Description : In shafts with keyways the allowable stresses are usually ------------ proportional to the twisting moment. a.25% b. 50% c. 75% d. 95%
Last Answer : c. 75%
Description : When two transformers are operating in parallel, they will share the load as under: (A) proportional to their impedances. (B) inversely proportional to their impedances. (C) 50% - 50% (D) 25%-75%
Last Answer : Ans: A High rating transformer has higher impedance. kVA rating α Impedance of transformer
Description : In the P generation, a tall plant is crossed with a short plant. The probability that an F2 plant will be tall is a. 50%. b. 75%. c. 25%. d. 100%.
Last Answer : b. 75%.
Description : The density of lead is 12 grams per cm3. A lead brick has a mass of 1.5 kilograms. Its dimensions are 10 cm by 5 cm by 4 cm. Is it: w) More than 75% hollow x) Between 50 and 75% hollow y) Between 25 and 50% hollow z) Between 0 and 25% hollow
Last Answer : ANSWER: Y -- BETWEEN 25 AND 50% HOLLOW
Description : Clearance volume in compressor should be A. As large as possible B. As small as possible C. About 50% of swept volume D. About 100% of swept volume
Last Answer : ANSWER : B
Description : The percent composition by mass of copper in anhydrous cupric sulfate is about: w) 10% x) 25% y) 40% z) 75%
Last Answer : ANSWER: C -- 40%
Description : For an engine operating on air standard Otto cycle, the clearance volume is 10% of the swept volume. The specific heat ratio of air is 1.4. The air standard cycle efficiency is a. 38.3 % b. 39.8 % c. 60.2 % d. 61.7 %
Last Answer : ANSWER d. 61.7%
Description : The tensile strength of concrete is about ________ of its compressive strength [ A ] 10% to 15% [ B ] 30% to 40% [ C ] 50% [ D ] 60% to 75%
Last Answer : [ A ] 10% to 15%
Description : In milk chilling plant, the usual secondary refrigerant is (a)ammonia (b)sodium silicate (c) glycol (d) brine
Last Answer : Ans: d
Description : The condition of refrigerant before entering the expansion or throttle valve, in a vapour compression system (a) dry vapour (b) wet vapour (c)liquid-vapour mixture (d) high pressure saturated liquid
Description : The C.O.P. of a refrigeration cycle with lowering of condenser temperature, keeping the evaporator temperatureconstant, will (a) increase (b) decrease (c) may increase or decrease depending on the type of refrigerant used (d) remain unaffected
Last Answer : Ans: a
Description : The C.O.P of a refrigeration cycle with increase in evaporator temperature, keeping condenser temperature constant, will (a) increase (b) decrease (c) remain unaffected (d) may increase or decrease depending on the type of refrigerant used
Description : The coefficient of performance is the ratio of the refrigerant effect to the (a) heat of compression (b) work done by compressor (c) enthalpy increase in compressor (d) all of the above
Description : Choose the wrong statement (a) Temperature of medium being cooled must be below that of the evaporator (b) Refrigerant leaves the condenser as liquid (c) All solar thermally operated absorption systems are capable only of intermittent operation (d) frost on evaporator reduces heat transfer
Description : Choose the correct statement (a) A refrigerant should have low latent heat (b) If operating temperature of system is low, then refrigerant with low boiling point should be used (c) Pre-cooling and sub-cooling bf refrigerant are same (d) Superheat and sensible heat of a. refrigerant are same
Last Answer : Ans: b
Description : For proper refrigeration in a cabinet, if the temperature and vapour pressure difference between cabinet and atmosphereis high, then (a) bigger cabinet should be used (b) smaller cabinet should ... tight vapour seal should be used (d) refrigerant with lower evaporation temperature should be used
Description : The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents (a) condensation of the refrigerant vapour (b) evaporation of the refrigerant liquid (c) compression of the refrigerant vapour (d) metering of the refrigerant liquid
Description : In a refrigeration cycle, the flow of refrigerant is controlled by (a) compressor (b) condenser (c) evaporator (d) expansion valve
Description : Aqua ammonia is used as refrigerant in the following type of refrigeration system (a) compression (b) direct (c) indirect (d) absorption
Description : A certain refrigerating system has a normal operating suction pressure of 10 kg/cm gauge and condensing pressure ofabout 67 kg/cm. The refrigerant used is (a) Ammonia (b) Carbon dioxide (c) Freon (d) Brine
Description : Highest pressure encountered in a refrigeration system should be (a) critical pressure of refrigerant (b) much below critical pressure (c) much above critical pressure (d) near critical pressure
Description : In vapour compression refrigeration system, refrigerant occurs as liquid between (a) condenser and expansion valve (b) compressor and evaporator (c) expansion valve and evaporator (d) compressor and condenser
Description : Which of the following is not a desirable property of a refrigerant (a) highmisibility with oil (b) low boiling point (c) good electrical conductor (d) large latent heat
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 flooded evaporator refrigerator, an accumulator at suction of compressor is used to (a) collect liquid refrigerant and prevent it from going to compressor (b) detect liquid in vapour (c) superheat the vapour (d) increase refrigeration effect
Description : In refrigerators, the temperature difference between the evaporating refrigerant and the medium being cooled should be (a) high, of the order of 25° (b) as low as possible (3 to 11°C) (c) zero (d) any value
Description : Condensing temperature in a refrigerator is the temperature (a) of cooling medium (b) of freezing zone (c) of evaporator (d) at which refrigerant gas becomes liquid
Description : One of the purposes of sub-cooling the liquid refrigerant is to (a) reduce compressor overheating (b) reduce compressor discharge temperature (c) increase cooling effect (d) ensure that only liquid and not the vapour enters the expansion (throttling) valve
Description : Absorption system normally uses the following refrigerant (a) Freon-11 (b) Freon-22 (c) C02 (d) ammonia.
Last Answer : Ans: e
Description : In refrigerator, liquid receiver is required between condenser and flow controlling device, if quantity of refrigerant for system is (a) less than 2 kg (b) more than or equal to 3.65 kg (c) more than 10 kg (d) there is no such consideration
Description : Highest temperature encountered in refrigeration cycle should be (a) near critical temperature of refrigerant (b) above critical temperature (c) atcritica. temperature (d) much below critical temperature
Description : The bank of tubes at the back of domestic refrigerator are (a) condenser tubes (b) evaporator tubes (c) refrigerant cooling tubes (d) capillary tubes
Description : The vapour pressure of refrigerant should be (a) lower than atmospheric pressure (b) higher than atmospheric pressure (c) equal to atmospheric pressure (d) could be anything
Description : In a vapour compression cycle, the refrigerant immediately after expansion valve is (a) liquid (b) sub-cooled liquid (c) saturated liquid (d) wet vapour