·         secondary winding has a greater number of turns than the primary winding

·         induced EMF is greater than the input signal

(a)  

·         secondary winding has lesser number of turns than the primary winding

·         induced EMF is lesser than the input signal

(a)  

·         electrical machine that changes the magnitude of an AC voltage or current from one value level to another

(a)  

·         the core is in a rectangular shape and the coils are both circular or rectangular in its form

·         windings are located on the opposite limbs of the core

·         in most of the large-size of a core-type transformer, round or circular cylindrical coils are used because the mechanical strength of it is high

(a)  

·         a simple rectangular form where the core surrounds the considerable portion of the windings

·         Both the primary and secondary windings are placed in one limb and the coils are wound in the form of a multi-layer disc type

·         insulated from each other by paper

(a)  

·         core loss and copper loss is zero

·         efficiency is 100%

·         There is no ohmic resistance drop so its voltage regulation is 0 %

·         flux generated in the primary gets fully linked to primary and secondary winding and there is zero flux leakage

·         hypothetical and cannot be realized practically

(a)  

·         has finite core and copper loss

·         depends on the loading and power factor, and it cannot be 100 % in any case

·         voltage regulation is always more than 0%.

·         entire flux does not gets linked to both winding and some amount of the flux gets leaked

(a)  

·         electrical power lost in the heat created by circulation of currents around the copper windings, considered the heaviest loss in transformers.

(a)  

·         eddy current and hysteresis losses, caused by lagging of magnetic molecules in response to the alternating magnetic flux within the core.

(a)  

·         provides low reluctance path for electromagnetic flux and supports the primary and secondary windings

·         made by stacking thin sheets of high-grade grain-oriented steel which are separated by thin insulating material

(a)  

·         Primary winding and secondary winding

·         consists of several turns of copper or aluminum conductors, insulated from each other and the transformer core

·         used for transformers depend upon the current rating, short circuit strength, temperature rise, impedance, and surge voltages

(a)  

·         most important part of transformers

·         failures can cause the most severe damage to transformers

·         required between the windings and the core

·         insulators should have high dielectric strength, good mechanical properties, and high-temperature withstand ability

·         Synthetic materials, paper, cotton, etc. are used as insulation in transformers

(a)  

·         Protects the core and the windings from the external environment

·         Serves as a container for oil and support for all other transformer accessories

·         made by fabricating rolled steel plates into containers

·         provided with lifting hooks and cooling tubes.

·         to reduce weight and stray losses, aluminum sheets are also used instead of steel plates

·         aluminum tanks are costlier than steel ones.

(a)  

·         for connecting incoming and outgoing cables

·         mounted upon the bushings and connected to the windings’ ends

(a)  

·         insulators that form a barrier between the terminals and the tank

·         mounted over the transformer tanks

·         safe passage for the conductors connecting terminals to the windings

·         made from porcelain or epoxy resins

(a)  

·         provides added insulation between the conducting parts, better heat dissipation, and fault detection features

·         Hydro-carbon mineral oil is used as transformer oil

·         composed of aromatics, paraffin, naphthene, and olefins

(a)  

·         present in all oil-immersed transformers that have a conservator tank

·         necessary to keep the oil-free from moisture.

·         As the temperature variations cause the transformer oil to expand and contact, air flows in and out of the conservator tank

(a)  

·         moved on top of the transformers and is located well above the tank and bushings

·         expands and contracts with an increase and decrease in temperature

·         provides adequate space for oil expansion

·         connected to the main tank through a pipe

·         level indicator is fitted to the conservator to indicate the oil level inside

(a)  

·         power lost in the transformer is dissipated in the form of heat

·         Dry transformers are mostly natural air-cooled but when it comes to oil-immersed transformers, a variety of cooling methods are followed

·         Depending on the kVA rating, power losses, and level of cooling requirements, radiators and cooling fans are mounted on the transformer tank

(a)  

·         acts as an emergency exit for oil and air gases inside a transformer

·         metallic pipe with a diaphragm at one end, held slightly above the conservator tank.

(a)  

·         used to adjust the secondary voltage of transformers

·         designed to change the turn ratio of the transformer as required

·         On-load tap changers and Off-load tap changers

(a)  

·         one of the most important parts of oil immersed transformers rated over 500kVA

·         an oil and gas actuated relay that is used to sense faults occurring in the parts immersed in the oil.

(a)  

transformer that is used to measure electrical quantities like current, voltage, power, frequency and power factor

(a)  

·         can be used in power systems to step down the voltage from a high level to a low level with the help of a 5A ammeter

·         The current in the secondary winding is proportional to the current in the primary winding as it generates current in the secondary winding

·         the primary winding consists of few turns, and it is connected with the power circuit in series. So, it is called a series transformer.

(a)  

·         can be used in power systems to step down the voltage from a high level to a lower level with the help of a small rating voltmeter which ranges from 110 Volts to 120 Volts.

·         The primary winding of the transformer includes a number of turns and it is connected in parallel with the circuit. So, it is called a parallel transformer.

(a)  

·         also known as a typical kind of isolation transformer

·         main function of this transformer is to alter the high voltage to the normal voltage like 240/120V to use in electric power distribution

(a)  

·         type of distribution transformer that is specially used for networks wherever a three-phase supply is not required

·         used for repairing overhead distribution loads in residential

·         applicable in industrial lighting, light commercial loads & power applications

(a)  

·        type of distribution transformer that is used to hold electrical energy from the main distribution circuit to a minor distribution circuit

·         transmits the current to a secondary distribution circuit and also reduces the voltage of the primary distribution circuit

·         reduce the voltage supply for the primary circuit based on the consumer requirement

(a)  

·         common power distribution system for a modern city in this world.

·         a classic underground residential distribution circuit system is an underground circuit in a loop type arrangement that fed at each end from an overhead circuit

(a)  

·         includes a locked steel cupboard that is arranged on a concrete pad

·         installed in places where they do not have space for a fenced enclosure

·         used with electric power distribution lines at an overhead electrical line for reducing the primary voltage to supply for the customers

·         single transformer of this type can serve many homes/a large building

(a)  

·         mounted on an electrical service pole at the height of the overhead cables.

·         Used for changing high distribution voltage to low

·         Tanks of the transformer can be shaped and protected from the corrosive materials & accumulation of water

(a)  

·         type of electrical transformer with only one winding

·         The “auto” prefix refers to the single coil acting alone (Greek for “self”) – not to any automatic mechanism

·         primary and secondary windings are linked together both electrically and magnetically reducing the cost over conventional transformers

(a)  

The manufacturer’s name or initials

(a)  

Number for identification

(a)  

To be specified if DC

(a)  

To be specified if single or three phase

(a)  

The rated value for the current flowing through a winding’s line terminals at rated load. The maximum current for which the winding is design

(a)  

The frequency at which the transformer is intended to work (AC)

(a)  

The apparent power in VA, kVA, or MVA for AC, W or kW for DC

(a)  

To be specified if the transformer is greater than or equal to 1 Kva

(a)  

The value of the main voltage which is intended to be applied to or induced in the primary winding. The maximum voltage for which the transformer is designed in normal operation

(a)  

The voltage which is generated for the transformer’s secondary line terminals with or without load (depending on the standard)

(a)  

Must be specified if the transformer weighs more than 18 kg.

(a)  

Continuous or intermittent operation

(a)  

protection system used for a power transformer depends on the transformer's categories.

 

(a)  

a code which indicates the cooling type

(a)  

·         an electrical device that accepts single-phase AC power and outputs single phase AC

·         used in the distribution of power in non-urban areas as the overall demand and costs involved are lower than the 3-phase distribution transformer

·         used as a step-down transformer to decrease the home voltage to a suitable value without a change in frequency

·         uses a single phase alternating current

(a)  

·         made of three sets of primary and secondary windings

(a)  

·         very important for understanding the working of the transformer

·         When a sinusoidal voltage is applied to the primary of the transformer it draws magnetizing current to set up flux in the core.

·         flux links to the secondary and produces EMF.

·         Induced EMF in the primary and secondary of the transformer also depends on the turn ratio of the transformer

(a)  

·         secondary EMF to primary EMF

(a)  

·         primary turns to secondary turns

(a)  

·         alternating flux set up in the core when linked to turns of the primary and secondary winding induces voltage

·         depends on the number of turns and the rate of change of the flux.

·         EMF induced across the primary and secondary always opposes the applied voltage.

(a)  

·         if the alternating flux links to a coil the voltage is induced in the coil, the voltage induced in the primary and the secondary winding of the transformer.

·         RMS value of secondary induced EMF and primary induced EMF can be calculated using Faraday’s law of electromagnetic induction.

(a)  

·         power loss that occurs in the iron part the transformer.

·         depends on alternating frequency of the emf. There are two types : Eddy current loss (We) and Hysteresis loss (Wh)

(a)  

·         power loss that occurs in the primary and secondary coils when the transformer is on load

·         power is wasted in the form of heat due to the resistance of the coils.

(a)  

loss is proportional to the sequence of the load

(a)  

iron loss when the supply voltage and frequency are constants

(a)  

·         performed for determining the parameter of the transformer like their efficiency, voltage regulation, circuit constant, per unit value

·         performed without the actual loading and because of this reason the very less power is required for the test

·         gives a very accurate result as compared to the full load test

(a)  

·        always performed on the low-voltage side of the transformer.

·         Because, if it is performed on the high voltage side, the no-load current I0 would be inconveniently small and the applied voltage would be inconveniently large.

(a)  

·         always performed on high-voltage side i.e. the low voltage winding is always short-circuited.

·         If the test is performed on the low-voltage winding, then, the high voltage winding being short-circuited and hence, the voltage will be inconveniently low and the current would be inconveniently high.

(a)  

This is defined as the electric potential produced by either an electrochemical cell or by changing the magnetic field.

(a)  

hen the changing flux links with the core itself, it induces emf in the core which in turns sets up the circulating current called

(a)  

If we place multiple cables together and pass current through them, then the magnetic fields will combine to create?

(a)