Description : Which of the following are optimum temperature conditions for making benzenediazonium chloride from aniline? (a) 0°C to 10°C (b) 20°C to 25°C (c) 30°C to 40°C (d) 45°C to 50°C
Last Answer : 0°C to 10°C
Description : What is the life insulation if temperature increased by 10°C?
Last Answer : The life of the machine insulation decreases by half if the temperature of the insulation increases by 10°C.
Description : a zero-order reaction for every 10° rise of temperature, the rate is doubled. If the temperature is increased from 10°C to 100°C, the rate of the reaction will become: (1) 128 times (2) 256 times (3) 512 times (4) 64 times
Last Answer : 512times
Description : 2. In a zero-order reaction for every 10° rise of temperature, the rate is doubled. If the temperature is increased from 10°C to 100°C, the rate of the reaction will become: (1) 128 times (2) 256 times (3) 512 times (4) 64 times
Last Answer : 256 times
Description : Lumirhodopsin is stable only at temperature below (A) –10°C (B) –20°C (C) –40°C (D) –50°C
Last Answer : Answer : D
Description : Thermophilic micro-organism grow well at temperature– 1) 10°C – 20°C 2) 20°C – 40°C 3) 50°C – 60°C 4) 5°C – 7°C
Last Answer : 3) 50°C – 60°C
Description : A steel rod of sectional area 250 sq. mm connects two parallel walls 5 m apart. The nuts at the ends were tightened when the rod was heated to 100°C. If steel = 0.000012/C°, Esteel = 0.2 MN/mm2 , the ... N/mm2 (B) 100 N/mm2 (C) 120 N/mm2 (D) 150 N/mm2 Answer: Option
Last Answer : (C) 120 N/mm
Description : The average temperature of sewage in India, is A. 10°C B. 15°C C. 20°C D. 25°C
Last Answer : ANS: C
Description : Copper is often used as an electrical conductor because it _______________. A. has high resistance at low temperatures B. has a highly polished surface C. is able to pass current with little opposition D. holds insulation together well
Last Answer : Answer: C
Description : The rate of a chemical reaction is almost doubled for every 10°C rise in temperature. The rate will increase __________ times, if the temperature rises from 10 to 100°C. (A) 256 (B) 512 (C) 112 (D) 612
Last Answer : (B) 512
Description : A batch adiabatic reactor at an initial temperature of 373°K is being used for the reaction, A → B. Assume the heat of reaction is - 1kJ/mole at 373°K and heat capacity of both A and B to be constant and equal ... rise after a conversion of 0.5 will be: (A) 5°C (B) 10°C (C) 20°C (D) 100°C
Last Answer : (B) 10°C
Description : Walls of a cubical oven are of thickness l, and they are made of material of thermal conductivity k. The temperature inside the oven is 100°C and the inside heat transfer co-efficient is 3k/l'. If the wall temperature ... wall temperature in degree centigrade? (A) 35.5 (B) 43.75 (C) 81.25 (D) 48.25
Last Answer : (C) 81.25
Description : Volatile oil are those oil which can evaporate at : a. 25°C b. 40°C c. 50°C d. 65°C
Last Answer : 25°C
Description : Process conditions in fermentator used for production of penicillin is (A) 25°C, 2 atm (B) 50°C, l0 atm (C) 30°C, 200 mm Hg (absolute) (D) 90°C, 45 atm
Last Answer : (A) 25°C, 2 atm
Description : The boiling point of ammonia is (a) -100°C (b) -50°C (c) - 33.3°C (d) 33.3°C.
Last Answer : Ans: c
Description : A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system (A) its internal energy (U) decreases and its entropy (S) increases (B) U and S both decreases (C) U decreases but S is constant (D) U is constant but S decreases
Last Answer : (B) U and S both decreases
Description : Which of the following is not a reversible process? (A) Expansion of an ideal gas against constant pressure (B) Atmospheric pressure vaporisation of water at 100°C (C) Solution of NaCl in water at 50°C (D) None of these
Last Answer : C) Solution of NaCl in water at 50°C
Description : The turn-off time of a thyristor is 30 is at 50°C. What is its turn-off time at 100°C ?
Last Answer : The turn-off time of a thyristor is 30 is at 50°C. What is its turn-off time at 100°C ? 60 microsecond
Description : Which of the listed conditions could indicate the need for cleaning electrical insulation? A. Low ambient temperature B. Low operating temperature C. High dielectric strength D. Low megger readings
Last Answer : Answer: D
Description : Which of the listed classes of electrical insulation is suited for the highest operating temperature? A. Class 90 (O) B. Class 105 (A) C. Class 130 (B) D. Class 180 (H)
Description : Electrical insulation is classed by the _____________. A. International Association of Electrical Manufacturers B. approximate operating voltage and current expected C. U.S. Coast Guard D. temperature stability of the manufacturing material(s)
Description : An insulation resistance test is performed on a particular piece of electric equipment. In addition to the resistance reading, what information listed below should be entered in the electrical log? A. ... D. The complete nameplate data from the resistance test instrument used to obtain the reading.
Last Answer : Answer: B
Description : The pH of water at 25°C is 7. When it is heated to 100°C, then what will be the pH of water?
Last Answer : – Remains same
Description : Bence jones proteinurial characterized by (A) Non-heat coagulability (B) Heat coagulability at 100°C (C) Heat coagulability at 45 to 60°C (D) Precipitation at 25°C
Last Answer : Answer : C
Description : The density of water is 1 g/cc. This is strictly valid at – (1) 0°C (2) 4°C (3) 25°C (4) 100°C
Last Answer : (2) 4°C Explanation: Water never has an absolute density because its density varies with temperature. Water has its maximum density of 1 g/cm3 at 4 degrees Celsius. When the temperature changes from either greater or ... 1 g/cm3. Water has the maximum density of 1 g/cm3 only when it is pure water.
Description : The density of water is 1 g/cc. This is strictly valid at (1) 0°C (2) 4°C (3) 25°C (4) 100°C
Last Answer : 4°C
Description : Hot water (0.01 m3 /min) enters the tube side of a counter current shell and tube heat exchanger at 80°C and leaves at 50°C. Cold oil (0.05 m3 /min) of density 800 kg/m3 and specific heat of ... mean temperature difference in °C is approximately (A) 32 (B) 37 (C) 45 (D) 50
Last Answer : (A) 32
Description : Which of the listed groups of electrical insulation materials is best suited for the highest operating temperatures? A. impregnated cotton and silk B. unimpregnated paper and cotton C. pure glass and quartz D. mica and porcelain with bonding agents
Description : Electrical machinery insulation will break down more rapidly due to _________________. A. low loading of motors and generators B. frequent megger testing C. high temperatures and vibration D. high operating frequencies
Description : When troubleshooting motor controllers, a shorted relay or contactor coil is often indicated by _______________. A. a resistance reading of 'infinity' on an ohmmeter B. charred insulation and/or a blown ... of the coil's leads to ground D. a higher-than-normal voltage reading across the winding
Description : A generator has been exposed to water and is being checked for its safe operation. Therefore, it is necessary to _______________. A. check for shorted coils with a growler B. take moisture readings with a ... a megger D. ground the commutator, or slip rings and run it at half load for 12 hours
Description : A megger is being used to test the insulation of an AC generator. The resistance value of a dry, clean winding will _____________. A. continue to rise as test potential is maintained, ... , becoming fairly steady after 5-7 minutes D. stabilize after approximately 2-4 minutes of fluctuation
Last Answer : Answer: A
Description : You are testing the insulation in an AC generator with a megohmeter. The resistance value of a dry, clean winding will ____________. A. continue to rise as the test potential is maintained, ... fairly steady after 5 to 7 minutes D. stabilize after approximately 2 to 4 minutes of fluctuation
Description : The purpose of the 'heater resistors' for the winch circuit shown in the illustration is to _______________. EL-0102 A. limit the current in the heater circuit B. dispel moisture in the ' ... panel C. keep the winch brake housing below the dew point D. maintain winch motor operating temperature
Description : Pick out the wrong statement (A) A horizontal line on the humidity chart indicates the temperature changes at constant molal humidity (B) When water is cooled from 80 to 70°C by exposure ... & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure
Last Answer : (D) Relative saturation of unsaturated mixture of water vapor & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure
Description : For every 10°C rise in temperature, the rate of chemical reaction doubles. When the temperature is increased from 30 to 70°C, the rate of reaction increases __________ times. (A) 8 (B) 12 (C) 16 (D) 32
Last Answer : (C) 16
Description : The reaction rate almost gets doubled for 10°C rise in temperature. This is due to the fact that the (A) Increased temperature reduces the activation energy (B) Fraction of molecules having threshold energy increases (C) Collision frequency increases (D) Value of threshold energy decreases
Last Answer : (B) Fraction of molecules having threshold energy increases
Description : Unless it can be shown that a 45°C ambient temperature will not be exceeded, motors within a machinery space must be designed for an ambient temperature of _____________. A. 45°C B. 50°C C. 55°C D. 60°C
Description : Which of the conditions listed will indicate the need to clean the insulation on the windings of an electric motor? A. Higher than normal operating temperature. B. Excessive vibration at normal speed. C. Sparking at the brushes. D. High megger readings.
Description : The need for insulation cleaning may be determined by _____. A. visual inspection for dirt accumulation B. high megger readings C. low operating temperature D. the time period since the last cleaning
Description : A three-phase electrical system is equipped with ground detecting lamps. If one of the lamp goes dark and the other two burn normally before and after the test switch is operated, this indicates _______________. ... of the three phases D. the voltage to the dark lamp is less than that of the system
Description : Basic electrical motor action depends on _______________. A. a conductor rotated within a magnetic field B. a current carrying conductor placed in a magnetic field C. the relative force of the commutator and commutating poles D. the relative force of the armature and interpoles
Description : Grease coatings on electrical contact surfaces increase contact resistance and should be removed with a/an _______________. A. small wire brush B. compressed air jet C. clean dry cloth D. 10% solution carbon solvent and water
Description : When electrical cables penetrate watertight bulkheads, _______________. A. they should be grounded on either side of the bulkhead B. they must be bent to a radius of six diameters C. a watertight stuffing tube capable of accepting packing should be employed D. they should be secured by a clamp
Description : If a magnetic controller contact fails to pick up when the operating coil is energized, one possible cause may be _______________. A. low spring pressure B. low voltage to the coil C. the residual magnetism of the contact faces D. dirty contact faces
Description : The 'function generator' of the control circuit illustrated _______________. EL-0095 A. can be programmed to produce a non-linear output for a linear input depending on operating conditions B. is used for ... which or how many engines are needed for a required vessel speed D. all of the above
Description : If 450 volts AC were measured across the load as shown in the illustration it would indicate a/an _______________. EL-0083 A. open winding between 'H1' and 'X1' B. properly operating circuit C. open winding between 'X1' and 'X4' D. ground on one side of 'Ep'
Description : The operator of electrical motors should keep a constant check on the loads they carry because _____________. A. low loads necessitate frequent insulation cleaning B. exceeding nameplate values shortens ... wasted if full loading is not utilized D. power factor correction methods are load dependent
Description : Which of the following is NOT an indicator of economic development? (1) Increased per capita income (2) Decreased infant mortality (3) Increased life expectancy at birth (4) Decreased women participation in job marke
Last Answer : (4) Decreased women participation in job market
Description : A man weighing 96 kg, consists of approximately _______________ litres of water. (a) 501 (b) 66.51 (c) 821 (d) 421
Last Answer : Ans:(b)