Q 25-30
A process fluid at 50 m3/hr, with a density of 0.96, is flowing in a heat exchanger and is to be cooled from 36oC to 29oC. The fluid specific heat is 0.78 kcal/kg. If the chilled water range across the heat exchanger is 5oC,the chilled water flow rate is
a) 67.2 m3/hr b) 52.42 m3/hr c) 50 m3/hr d) none of the above
b) 52.42 m3/hr
A Plant wants to replace the existing 100 TR water cooled vapour compression refrigeration system with a waste heat driven vapour absorption chiller. The capacity of the existing cooling tower
a) needs no change b) is to be doubled c) is to be raised to 1.2 times d) none of the above
b) is to be doubled
Which one from the following types of cooling towers consumes least power for the same operating conditions?
a) counter flow film fill cooling tower b) cross-flow splash fill cooling tow c) counter flow splash fill cooling tower d) none of the above
a) counter flow film fill cooling tower
Two most important electrical parameters, which are to be monitored, among the following for safe operation of Diesel Generator set are:
a) voltage and ampere b) kW and kVA c) power factor and ampere d) kVA and ampere
b) kW and kVA
Select the incorrect statement:
a) harmonics occur as spikes at intervals which are multiples of the supply frequency
b) harmonics are not multiples of the fundamental frequency
c) induction motors are not the major sources of harmonics
d) transformers operating near saturation level create harmonics
b) harmonics are not multiples of the fundamental frequency
The inner tube of an L-type pitot tube is used to measure …… in the air duct
a) total pressure b) static pressure b) velocity pressure d) dynamic pressure
a) total pressure
Shaft power of the motor driving a pump is 30 kW. The motor efficiency is 0.92 and pump efficiency is 0.5. The power drawn by the motor will be
a) 65.2 kW b) 15 kW c) 30 kW d) 32.6 kW
d) 32.6 kW
Lux is defined as
a) ratio of luminous flux emitted by a lamp to the power consumed by the lamp b) one lumen per square meter c) one lumen per square feet d) none of the above
b) one lumen per square meter
In a DG set, the generator capacity is 1000 kVA with a rated power factor 0.8. It is consuming 150 litre per hour diesel oil. If the specific fuel consumption of this DG set is 0.25 litres/ kWh at that load, then what is the kVA loading of the set at 0.88 PF?
a) 682 kVA b) 800 kVA c) 750 kVA d) none of the above
a) 682 kVA
If the speed of centrifugal fan is reduced to 80% of its rated speed then the power drawn will _______% of its rated power:
a) 80% b) 51.2 % c) 40 % d) 64 %
b) 51.2 %
The intersection point of the centrifugal pump characteristic curve and the design system curve is the
a) pump efficiency point b) best efficiency point c) system efficiency point d) none of the above
b) best efficiency point
If water is flowing through a cooling tower at 120 m3/h with 5 deg C range, the load on cooling tower at an ambient wet bulb ambient temperature of 33 deg C is
a) 198.4 TR b) 357 TR c) 158 TR d) none of the above
a) 198.4 TR
Which among the following is the most energy efficient lamp for the same wattage rating?
a) HPMV b) GLS c) CFL d) Metal halide
d) Metal halide
The maximum unbalanced load between phases should not exceed _______ % of the capacity of the DG set
a) 10 b) 5 c) 1 d) none of the above
a) 10
The order of movement of thermal energy in HVAC system is:
a) Indoor air - Condenser water - Chilled water - Cooling tower - Refrigerant
b) Chilled water - Indoor air - Refrigerant-Cooling tower - Condenser water
c) Indoor air - Chilled water - Refrigerant-Condenser water- Cooling tower
d) Indoor air - Chilled water – Refrigerant - Cooling tower - Condenser water
c) Indoor air - Chilled water - Refrigerant-Condenser water- Cooling tower
In case of increased suction lift from open wells, the pump delivered flow rate
a) increases b) decreases c) remains same d) none of the above
b) decreases
In a plant, the loading on a transformer was 1000 kVA with the power factor of 0.88. The plant improved the power factor to 0.99 by adding capacitors on the load side. The release in transformer loading( kVA) will be
a) 111 b) 889 c) 999 d) none of the above
a) 111
_____ is a measure of effect of light on the perceived colour of objects
a) lux b) lumens c) CRI d) lamp circuit efficacy
c) CRI
The capacity of largest motor that can be started in the given DG set is…… of kVA rating of DG set
a) 25% b) 50% c)75% d)100%
b) 50%
Which one of the following device will help to eliminate the hunting problems normally associated with capacitor switching?
a) Maximum Demand Controller
b) Intelligent Power Factor Controller (IPFC) c) Soft Starter
d) Eddy Current Drives
b) Intelligent Power Factor Controller (IPFC)
In pumping systems where static head is a high proportion of the total, the appropriate solution is
a) install two or more pumps to operate in parallel b) install two or more pumps to operate in series c) install two or more pumps to operate in independent operation d) none of the above
b) install two or more pumps to operate in series
The wet bulb temperature normally chosen for designing of cooling tower is
a) average maximum wet bulb for rainy months b) average maximum wet bulb for summer months c) average minimum wet bulb for summer months d) average maximum wet bulb for winter months
b) average maximum wet bulb for summer months
Which of the following is the best definition of illuminance?
a) luminous flux incident on an object per unit area b) flux density emitted from an object without regard for direction c) time rate of flow of light energy d) flux density emitted from an object in a given direction
a) luminous flux incident on an object per unit area
The jacket cooling water in a diesel engine flows at 12.9 m3/hr with a range of 10oC and accounts for 30% of the engine input energy. What will be the hourly Diesel consumption in kg with a calorific value of 10,000 kcal/kg
a) 43 b) 12.9 c) 17.3 d) none of the above
a) 43
The occupancy sensors in a lighting installation are best suited for
a) conference halls b) large production shops/hangars c) entrances of offices/buildings d) street lighting
a) conference halls