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Answer :

Much higher efficiency of transformer compared with that of electrical motors of the same power.

Related questions

Last Answer : The efficiency of transformer is Greater than electrical Machine because there is no rotational losses in transformer and there is no air gap losses in transformer so losses is less in transformer compare to electrical machine so efficiency is higher in case of transformer.

Description : The efficiencies of transformers compared with that of electric motors of the same power are?

Last Answer : Transformers have high efficiency than the same ratted motors

Description : Why the efficiency of the Induction motor is less compared to transformer?

Last Answer : Answer: Induction motor and Transformer operates on the same principle that power is transferred to secondary by mutual induction. But in transformer, flux will be traveled from primary to ... compared to transformer which also results in less efficiency for induction motor compared to transformer.

Description : (a) Define permeability. (b) Define MMF. (c) Define form factor of an alternating quantity. (d) Define frequency and time period of an alternating quality. (e) Define transformation ratio of transformer. ... and state the meaning of each term used. (g) Give two applications of single phase motors. 

Last Answer : Permeability : It is the ability of a magnetic/Non magnetic material to allow setting up of flux in it.  MMF : The magneto motive force (MMF) is the force required to setup flux in a magnetic / ... applications of single phase motors : Water pumps, ceiling fan, lathe machine

Description : Complete maintenance of electrical motors should include periodic checks for machine _____________. A. vibration B. watertight integrity C. speed droop D. reactive power

Last Answer : Answer: A

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

Last Answer : Answer: B

Description : What will be the efficiency when the transformer operates at unity power factor and 60% of full load 

Last Answer : What will be the efficiency when the transformer operates at unity power factor and 60% of full load 96.5%

Description : For same power output and same r, as compared to 2- stroke engines, four stroke SI engines have (a) Higher fuel consumption (b) Lower thermal efficiency (c) Highest exhaust temperatures (d) Higher thermal efficiency

Last Answer : Ans :d

Description : Which of the following test is usually conducted to determine the efficiency of traction motors ? (A) Field’s test (B) Swinburne’s test (C) Hopkinson’s test (D) Retardation test.

Last Answer : Which of the following test is usually conducted to determine the efficiency of traction motors ? (A) Field’s test (B) Swinburne’s test (C) Hopkinson’s test (D) Retardation test.

Last Answer : The range of efficiency for shaded pole motors is 5% to 35%.

Description : Slip ring induction motor advantages and disadvantages compared to squirrel cage motors?

Last Answer : Advantages: High starting torque with low starting current Smooth acceleration under heavy loads No abnormal heating during starting Good running characteristics after external rotor resistances are cut out ... cage motors The speed regulation is poor when run with resistance in the rotor circuit

Description : As compared to shunt and compound DC motors, the series DC motor will have the highest torque because of its comparatively ____________ at the start. (A) Lower armature resistance. (B) Stronger series field. (C) Fewer series turns. (D) Larger armature current.

Last Answer : (D) Larger armature current.

Description : As compared to shunt and compound motors, series motor has the highest torque because of its comparatively .......... at the start.

Last Answer : As compared to shunt and compound motors, series motor has the highest torque because of its comparatively stronger series field at the start.

Description : The most common source of excitation for synchronous motors is a/an ______________. A. stepup transformer B. half-wave rectifier C. DC supply D. AC supply

Last Answer : Answer: C

Description : As shown in the illustration, the electrical symbol is used to indicate which of the listed types of motors? EL-0054 A. Shunt motor. B. Series motor. C. Compound motor. D. Tri-field motor.

Last Answer : Answer: C

Description : Electrical failures in motors are caused by the breakdown of insulation, which may be caused by _____________. A. penetration of moisture B. accumulation of dirt C. overheating D. all of the above

Last Answer : Answer: D

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

Last Answer : Answer: C

Description : The greatest detrimental effect on idle electrical equipment, such as cargo pump motors, is the _____________. A. loss of residual magnetism B. absorption of moisture in the insulation C. insulation varnish flaking D. dirt collecting on the windings

Last Answer : Answer: B

Description : Straight silicon steel (containing Si from 0.5 to 5%) because of their low hysteresis loss and high magnetic permeability are used for electrical appliances. Which of the following electrical ... /generators (B) Generators and small motors (C) Induction motors (D) High frequency transformers

Last Answer : (D) High frequency transformers

Description : DC motors converts electrical into ___ energy. A. Mechanical B. Wind C. Electric D. None

Last Answer : A. Mechanical  

Description : Explain the following Energy conservation methods of electrical motor : (a) Rewinding of motors (b) Operating in star mode

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Description : Transformer efficiency

Last Answer : Transformer efficiency

Description : Define efficiency of a transformer. State its formula.

Last Answer : the efficiency of a transformer is defined by the ratio of output of the transformer to the input to it. this is denoted by the symbol called eita. Efficiency = output/Input*100%

Description : A transformer operates 24 hours day at full -load. It's full -load efficiency is :  (A) equal all day efficiency (B) more than all -day efficiency (C) less than all -day efficiency (D) equal to maximum efficiency

Last Answer : A transformer operates 24 hours day at full -load. It's full -load efficiency is : equal all day efficiency 

Description :  A transformer has maximum efficiency at 3/4 full load. The ratio of its iron losses and full load copper loss is : -  a) 16/9 b) 4 / 3 c) 3/4 d) 9 /16

Last Answer :  A transformer has maximum efficiency at 3/4 full load. The ratio of its iron losses and full load copper loss is : -  9 /16

Last Answer : Transformer efficiency is maximum when copper losses are equal to iron losses.

Last Answer : As compared to an amplifier, a transformer cannot Increase the output Power

Description : If the performance of diesel engine of different sizes, cylinder dimensions and power rating are to be compared, which of the following parameters can be used for such comparison? (a) Swept volume (b) Air fuel ratio (c) Specific brake fuel consumption (d) Volumetric efficiency

Last Answer : Ans :c

Description : Multistage compression of air as compared to single stage compression offers the advantage of (A) Power saving per unit weight of air delivered (B) Moisture elimination in the inter-stage cooler (C) Increased volumetric efficiency (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

Description : A double acting reciprocating pump compared to a single acting pump (of almost same size working under same pressure levels) would give almost double (A) Head (B) Discharge (C) Efficiency (D) None of these

Last Answer : (B) Discharge

Description : The efficiency of an Otto engine compared to that of a diesel engine, for the same compression ratio will be (A) More (B) Less (C) Same (D) Data insufficient to predict

Last Answer : (A) More

Description : If both Stirling and Carnot cycles operate within the same temperature limits, then efficiency of Stirling cycle as compared to Carnot cycle  (a) more  (b) less  (c) equal  (d) depends on other factors  (e) none of the above.

Last Answer : Answer : c

Description : At what power maximum efficiency of power transformer and distribution transformer is designed

Last Answer : Maximum efficiency of the transformer is attained at certain load factor (α) when core losses of transformer is equal to the copper losses. PCore loss = α ^2 X PCopper loss From the ... the day. Hence distribution transformers are designed to have maximum efficiency at 50% of the rated full load

Description : Define the percentage voltage regulation and efficiency of a power transformer.  

Last Answer : Voltage regulation is the difference between no load voltage and full load voltage by no load voltage. Voltage regulation = No load voltage - Full load voltage / No load voltage. Voltage regulation is mentioned ... . % Efficiency = Output in watts * 100 / Output in watts + losses. 

Description : A simple phase transformer has a maximum efficiency of 90% at full load and unity power factor. Efficiency at half load at the same power factor is  (A) 86.7% (B) 88.26% (C) 88.9% (D) 87.8%

Last Answer : A simple phase transformer has a maximum efficiency of 90% at full load and unity power factor. Efficiency at half load at the same power factor is 87.8%

Last Answer : The efficiency of a power transformer is of the order of 98 percent.

Description : What is defined as the ratio of the net electrical power output to the rate of fuel energy input?  A. Combustion efficiency  B. Thermal efficiency  C. Overall efficiency  D. Furnace efficiency

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Description : Draw the power and control circuit for motors using autotransformer type starter.

Last Answer : Draw the power and control circuit for motors using autotransformer type starter.

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Description : A transformer in an electric circuit serves to ____________. A. generate its own electrical power B. transform electrical energy into mechanical energy C. increase or decrease circuit voltage as required D. convert AC current to DC current

Last Answer : Answer: C

Description : In a step-up or step-down transformer, electrical power is transferred from one circuit to another without change in

Last Answer : In a step-up or step-down transformer, electrical power is transferred from one circuit to another without change in frequency

Description : Among mammals, the efficiency of ventilation of lungs as compared to reptiles and birds is better developed by the presence of

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Description : what is the efficiency of this product compared to other leading enrgy saving air conditioners?

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Description : Why efficiency of gas turbines is lower compared to I.C. engines ?

Last Answer : In gas turbines, 70% of the output of gas turbine is consumed by compressor. I.C. engines have much lower auxiliary consumption. Further combustion temperature of I.C. engines is much higher compared to gas turbine.

Description : The catalytic efficiency of two different enzymes can be compared by the (a) formation of the product (b) pH of optimum value (c) Km value (d) molecular size of the enzyme.

Last Answer : (c) Km value

Description : In a furnace employing forced draught as compared to induced draught, (A) Air is sucked in, so air leaks are more and hence the furnace efficiency is reduced (B) The fan operates hot and hence blades are liable to corrosion and erosion (C) Positive pressure exists in the furnace (D) None of these

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Last Answer : (D) All (A), (B) and (C)

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