The efficiency of a transformer, under heavy loads, is comparatively low because?

1 Answer

Answer :

The efficiency of a transformer, under heavy loads, is comparatively low because copper loss becomes high in proportion to the output.

Related questions

Description : State why a transformer always have an efficiency of more than 90%.

Last Answer : As transformer is static device with no moving parts, the losses due to friction & windage are completely absent. Hence transformer has efficiency of more than 90%.

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

Last Answer : An ideal transformer will have maximum efficiency at a load such that copper loss equal to iron loss.

Description : For a transformer, operating at constant load current, maximum efficiency will occur at?

Last Answer : For a transformer, operating at constant load current, maximum efficiency will occur at unity power factor.

Description : Step-down transformer converts high voltage and low current into:  (A) How voltage and high current (B) High voltage and low current (C) Low voltage and high current (D) None of the above

Last Answer : Step-down transformer converts high voltage and low current into: Low voltage and high current

Description : Transformer efficiency

Last Answer : Transformer efficiency

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 

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.

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

Description : Define armature reaction in an alternator. Explain the effect of armature reaction at various P.F. of loads of alternator.

Last Answer : Armature Reaction: The effect of armature flux on main flux is called as armature reaction.  Armature Reaction at Various Power Factors: When armature is loaded, the armature flux modifies ... lagging p.f. For capacitive loads the effect of flux is partly distorting and partly strengthening.

Description : If non-linear loads are connected to the power system, then (A) displacement power factor is same as the total power factor (B) displacement power factor is not equal to the total power ... factor is due to harmonic currents (D) total power factor is due to fundamental component of current

Last Answer : If non-linear loads are connected to the power system, then displacement power factor is not equal to the total power factor

Description : How to Hang a Heavy Mirror

Last Answer : How to Hang a Heavy Mirror Whether it's for vanity, decoration, or simply because you want a small room to look larger than it really is, hanging a large wall mirror is a good option. The ... any space look better and brighter. Follow these steps and install one in your home without any trouble.

Description : How to Drive in Heavy Rain

Last Answer : How to Drive in Heavy Rain It pays to be cautious, especially when driving in heavy rains. Accidents are aplenty when Mother Nature ravages the roads with heavy downpours so you should take extra precautions ... necessary. If you can, just stay home and enjoy some good old coffee and french toast!

Description : A heavy ladder resting on floor and against a vertical wall may not be in equilibrium, if?

Last Answer : A heavy ladder resting on floor and against a vertical wall may not be in equilibrium, if the floor and wall both are smooth surfaces.

Description : 48.During light loads, the transformer efficiency is low because A. Secondary output is low B. Transformer losses are high C. Fixed loss is high in proportion to the output D. Cu loss is small

Last Answer : C. Fixed loss is high in proportion to the output

Description : The efficiency of two identical transformers under load conditions can be determined by?

Last Answer : The efficiency of two identical transformers under load conditions can be determined by back-to-back test.

Last Answer : In a transformer, routine efficiency depends upon load current and power factor of load.

Last Answer : The maximum efficiency of a distribution transformer is at 50% full load.

Description : What is the heaviest thing you've ever moved?

Last Answer : Your dad. :D

Description : The secondary of a current transformer is always short-circuited under operating conditions because it?

Last Answer : The secondary of a current transformer is always short-circuited under operating conditions because it avoids core saturation and high voltage induction.

Last Answer : A transformer cannot raise or lower the voltage of a D.C. supply because Faraday's laws of electromagnetic induction are not valid since the rate of change of flux is zero.

Last Answer : The magnetising current of a transformer is usually small because it has small air gap.

Description : In an actual transformer the iron loss remains practically constant from no load to full load because?

Last Answer : In an actual transformer the iron loss remains practically constant from no load to full load because core flux remains practically constant.

Description : "Efficiency of thermal power station is low". — Justify. 

Last Answer : Justification: Efficiency of thermal power station is low":- Overall efficiency of T.P.P depends upon efficiency of boiler, turbine and alternator. The heat produced due to combustion of coal ... losses in thermal power plant is 71%, So efficiency of thermal power plant is less about 29% 

Description : How to Treat Low Blood Sugar ?

Last Answer : How to Treat Low Blood Sugar Low blood sugar or hypoglycemia is a condition usually experienced by diabetics but it's also possible to experience it without being a diabetic yourself. For diabetics, low ... identify the cause of the problem and help you get the proper treatment as soon as possible.

Description : Low Fat Barbecue Chicken

Last Answer : Low Fat Barbecue Chicken Dinner 4 lg. chicken breasts, cubed 1 green pepper, cut up 1 onion, cut up 1/2 to 3/4 c. barbecue sauce 1 to 2 bags Minute Rice, boil-in-bags Put chicken with green ... rice in center of plate. Make a nest and put chicken in center of rice. Looks nice and tastes great.

Description : Low-Calorie Dressing

Last Answer : Low-Calorie Dressing - serves 6 salad dressing 1 6-ounce can vegetable or tomato juice 1 tbsp very finely chopped onion 1 tbsp very finely chopped celery 1 tbsp very finely chopped bell pepper ... , oregano, tarragon or herb seasoning for the parsley will give a range of flavored salad dressing.

Description : Name two methods for measurement of low, medium and high resistance. Give one advantage and one limitation of V- I method.

Last Answer : Methods for measurement of low resistance:  1. Ammeter voltmeter method  2. Kelvin's bridge method  3. Ohm meter method  4. Potentiometer method  5. Digital/analog multi-meter ... must be infinity for perfectly accurate measurement which is not possible.  2. Connection errors.

Description : Name the method used to measure following resistances:- (i) Low resistance (ii) Medium resistance (iii) Insulation resistance (iv) Earth resistance.

Last Answer : Following are the methods used to measure resistances:-  (i) Low resistance: 1.Voltmeter-Ammeter Method 2. Kelvin's Double bridge Method  (ii) Medium resistance: 1.Voltmeter-Ammeter Method 2. ... of Charge Method  (iv) Earth resistance : 1. Fall of Potential Method 2. Earth tester

Description : State the range for low and medium resistance.

Last Answer : Low resistances: less than 1 ohm.  Medium resistances: 1 ohm to 0.1 Mega ohm. 

Description : Which of the following is the least expensive protection for over current in low voltage system?  (A) Rewireable fuse (B) Isolator (C) Oil Circuit breaker (D) Air break circuit breaker

Last Answer : Which of the following is the least expensive protection for over current in low voltage system?  (A) Rewireable fuse (B) Isolator (C) Oil Circuit breaker (D) Air break circuit breaker

Description : In a 741 Op-Amp, there is 20 dB/decade fall-off starting at a relatively low frequency. This is due to the (A) applied load (B) internal compensation (C) impedance of the source (D) power dissipation in the chip

Last Answer : In a 741 Op-Amp, there is 20 dB/decade fall-off starting at a relatively low frequency. This is due to the internal compensation

Description : Accurate measurement of very low resistances is possible with (A) Megger (B) Wheatstone Bridge (C) Kelvin’s Double Bridge (D) Wagner’s Earthing Device

Last Answer : Accurate measurement of very low resistances is possible with Kelvin’s Double Bridge

Last Answer : Turbine used for low head is Kaplan turbine.

Description : At very low frequencies a series R-C circuit behaves as almost purely?

Last Answer : At very low frequencies a series R-C circuit behaves as almost purely capacitive.

Description : In an AC. circuit, a low value of kVAR compared with kW indicates?

Last Answer : In an AC. circuit, a low value of kVAR compared with kW indicates high power factor.

Last Answer : In a low power factor wattmeter the pressure coil is connected to the load side of the current coil.

Last Answer : A synchronous machine with low value of short-circuit ratio has lower stability limit.

Last Answer : The primary reason for low power factor is supply system is due to installation of induction motors.

Last Answer : A low utilization factor for a plant indicates that plant is used for stand by purpose.

Last Answer : To protect most of the electrical equipment handling low power, the types of relays used are thermocouple, electronic and bimetallic.

Description : What is the definition of extra low voltage?

Last Answer : Extra-low voltage (ELV) is an electricity supply voltage in a range which carries a low risk of dangerous electrical shock.

Description : At which time power factor of the induction motor is low?

Last Answer : The power factor of the inducction motor is low at the time of starting as compare to while the induction motor is running.

Description : write short notes on Low-pass filter.

Last Answer : low-pass filter (1) filter exhibiting frequency selective characteristic that allows low-frequency components of an input signal to pass from filter input to output unattenuated all high-frequency components are ... the bandwidth of the filter. A filter whose impulse response is a low-pass signal.

Last Answer : MOSFET have high current losses due to High on state resistance. Hence MOSFET is used for low power applications.

Description : Explain the effect of Harmonics on the Transformer.

Last Answer : Effect of Harmonics on the Transformer:  1. Core loss: Harmonic voltage increases the hysteresis and eddy current losses in the lamination. The amount of the core loss depends on ... small core vibrations.  5. Saturation problem: Sometimes additional harmonic voltage causes core saturation.

Description : List two special feature of welding transformer.

Last Answer : Special features of welding transformer: i) It is a step down transformer that reduces the source voltage to a voltage desired according to the demands of the welding process. ii) Having large primary turns and less ... V ii) Secondary voltage - 40 to 60 V iii) Secondary current - 200 to 600 A

Description : State two applications of isolation transformer

Last Answer : Applications of isolation transformer: i) Isolates the load equipment from supply ground: ii) Reduction of voltage spikes iii) It acts as a decoupling device. iv) Protects loads from harmonic distortion.

Description : Equivalent circuit of transformer

Last Answer : Equivalent Circuit Diagram of Transformer Referred to Primary: V1 -Primary Input voltage I1 - Input Current I0- Exciting current/ No load current Im- Magnetizing component ... equivalent of secondary terminal voltage ZL- Load impedance ZL ′- Primary equivalent of load impedance

Description : Single phase transformer

Last Answer : Single phase Transformer Transformer