67 The chemical used in breather for transformer should have the quality of
A. Ionizing air
B. Absorbing moisture
C. Cleansing the transformer oil
D. Cooling the transformer oil

1 Answer

Answer :

B. Absorbing moisture

Related questions

Description : 76 The changes in volume of transformer cooling oil due to variation of atmospeheric temperature during day and night is taken care of by which part of transformer? A. Conservator B. Breather C. Bushings D. Buchholz relay

Last Answer : A. Conservator

Last Answer : The chemical used in breather for transformer should have the quality of cleansing the transformer oil.

Description : What is the colour of silica gel in dry stage and when saturated with moisture in a breather?

Last Answer : Dry stage – Deep blue Saturated stage – Whitish pink

Last Answer : The function of breather in a transformer is to arrest flow of moisture when outside air enters the transformer.

Description : The chemical used in breather is A. Asbestos fibre B. Silica sand C. Sodium chloride D. Silica gel

Last Answer : Silica gel

Last Answer : The chemical used in breather is silica gel.

Description : Why transformer oil is used as a cooling medium?

Last Answer : When transformer oil is used as a coolant the heat dissipation by convection is 10 times more than the convection due to air. Hence transformer oil is used as a cooling medium.

Description : Why silica gel is used in breather?

Last Answer : The silica gel is used to absorb the moisture when the air is drawn from the atmosphere in to the transformer.

Description : 38] In a transformer the energy is conveyed from primary to secondary? A. Through cooling coil B. Through air C. By the flux D. None of the above

Last Answer : C. By the flux

Description : Material used inside the breather to prevent moisture entering the transformer is

Last Answer : Material used inside the breather to prevent moisture entering the transformer is silica gel

Description : What is the function of transformer oil?

Last Answer : A. Transformer Oil serves mainly two purposes 1. It acts as liquid insulation in electrical power transformer 2. It dissipates heat of the transformer i.e acts as coolant. In addition to these ... acid (C7, C8) esters are also becoming increasingly common as alternatives to naphthenic mineral oil.

Description : What is the function of transformer oil in a transformer ?

Last Answer : Transformer oil provides , (i)good insulation and (ii)cooling . Nowadays instead of natural mineral oil, synthetic oils known as ASKRELS (trade name ) are used. They are non-inflammable ... an electric arc do not decompose to produce inflammable gases. PYROCOLOR oil possess high dielectric strength.

Description : What is oil immersed type transformer?

Last Answer : In this type of transformer, oil is used as coolant. Entire assembly including core and windings is kept immersed in oil. The developed heat is transferred to the walls of tank through oil. Finally the heat is transferred to the surrounding air from tank wall by radiation.

Description : 63 The dielectric strength of transformer oil is expected to be A. 1kV B. 33kV C. 100kV D. 330 kV

Last Answer : B. 33kv

Description : 45 The function of conservator in a transformer is A. To protect against internal fault B. To reduce copper as well as core losses C. To cool the transformer oil D. To take care of the expansion and contraction of transformer oil due to variation of temperature of surroundings

Last Answer : D. To take care of the expansion and contraction of transformer oil due to variation of temperature of surroundings

Description : 19 Transformer cores are built up from laminations rather than from solid metal so that A. Oil penetrates the core more easily B. Eddy current loss is reduced C. Less lamination is required for the windings D. Turn ratio is higher than voltage ratio

Last Answer : B. Eddy current loss is reduced

Description : Define Dielectric Strength for transformer oil. State its value for new transformer oil.

Last Answer : Dielectric strength is defined as the maximum voltage that can be applied to across to the Fulid with out electrical breakdown is called Dielectric strength.

Last Answer : A transformer oil must be free from moisture.

Last Answer : Gas is usually not liberated due to dissociation of transformer oil unless the oil temperature exceeds 150°C.

Description : The dielectric strength of transformer oil is expected to be?

Last Answer : The dielectric strength of transformer oil is expected to be 33 kV.

Description : What is the colour of silica gel in dry stage and when saturated with moisture in a breather?

Last Answer : Dry stage – Deep blue. Saturated stage – Whitish pink. 

Description : 46 The core used in high frequency transformer is usually A. Copper core B. Cost iron core C. Air core D.Mid steel core

Last Answer : C. Air core

Description : What are the types of cooling systems it transformers?

Last Answer : A. 1. ONAN (oil natural, air natural) 2. ONAF (oil natural, air forced) 3. OFAF (oil forced, air forced) 4. ODWF (oil direct, water forced) 5. OFAN (oil forced, air forced)

Description : How the heat dissipation is improved by providing the cooling tubes?

Last Answer : The cooling tubes will improve the circulation of oil. The circulation of oil is due to effective pressure heads produced by columns of oil in tubes. The improvement in cooling is accounted by taking the specific heat dissipation due to convection as 35% more than that without tubes.

Description : Why cooling tubes are provided?

Last Answer : Cooling tubes are provided to increase the heat dissipating area of the tank.

Description : What are the factors to be considered for choosing the method of cooling?

Last Answer : The choice of cooling method depends on KVA rating of transformer, size, application and the site conditions where it will be installed.

Description : List some methods of cooling of transformers.

Last Answer : A:Air natural, Air blast, Oil Natural, Oil natural air forced, Oil natural water forced, Oil forced, Oil forced air natural, Oil forced air natural, Oil forced water forced.

Description : What is the use of breather in the transformer?

Last Answer : Breather is a bottle shaped steel tube, which is attached to one side of conservator to allow the air to pass in and out of the tank or conservator through the calcium chloride and silica gel, ... contained in the air. When the silica gel absorb the moisture its colour changes from blue to pink.

Description : What is a Transformer ?

Last Answer : Ans : A transformer is a static piece of apparatus which transforms electrical energy from one Circuit to another circuit without changing the frequency either stepping up or stepping down the voltage .

Description : What are the transformer losses?

Last Answer : Answer: TRANSFORMER LOSSES - There are mainly two kinds of losses in a transformer namely 1. Copper loss (ohmic loss) and 2.magnetic loss (core loss). Copper losses are caused by the ... ohmic loss the following two losses are also present in the transformer stray load loss and dielectric loss.

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 : What happen when Transformer is given DC supply ?

Last Answer : When DC supply is given to the transformer primary winding no back emf is induced in the transformer. Importance of Back emf is that it limits the current drawn by the machine. In the absence ... in burning down of primary winding. So when dc supply is given to transformer primary windings will burn

Description : During No load why the power factor of the transformer is very low ?

Last Answer : Current flowing through the transformer consists of two components. Magnetizing current (Im) which is in quadrature (90 0 ) to the applied voltage and in phase current which is in phase to the applied voltage ... power factor of transformer during no load condition will by in the order of 0.1 to 0.2

Description : What is the supply rated o/p if two single phase transformer connect to give three phase o/p from a three phase I/p?

Last Answer : A. Each transformer is only capable of supplying 86.6%of its o/p rating

Description : How to connect two single phase transformer to give three phase o/p from a three phase I/p ?

Last Answer : A. They would have to connect in an open-delta.

Description : What is the 3 ph transformer ?

Last Answer : A. A 3ph transformer is that transformer which is equivalent to three single phase transformer but wound on one core and enclosed within one common case.

Description : What parameters or technical particulars are important to be considered while designing protection scheme of the transformer?

Last Answer : 1.Network Diagram showing the position of the transformer in the system 2.kVA or MVA rating of the transformer 3.Fault Level at the transformer 4.Voltage Ratio 5.Winding Connections 6.Per Unit ... Oil Filled 11.Length and area of cross section of the connecting leads between CTs and Relay Panel

Description : What can be the reasons for the failure of the transformer?

Last Answer : Answer: Transformer is one of the most expensive equipments in the Power System. Failure of the transformer can cause outage of power supply for even days. However, multiple things can go wrong with ... relays. 3.Short Circuits 4.Open Circuits 5.Earth Faults 6.Over Voltage 7.Reduced system frequency

Description : How Transformer Protection provided for internal faults?

Last Answer : 1.Bucholz Relay (1st Stage Alarm and 2nd Stage Trip) 2.Sudden Pressure Relay (1st Stage Alarm and 2nd Stage Trip) 3.Pressure Relief Valve (1st Stage Alarm and 2nd Stage Trip) 4.Pressure Switch ... 8.Gas Temperature Indicator (Alarm) 9.Silicon Breather (Passive - no alarm) 10.Smoke Detector (Alarm)

Description : How does change in frequency affect the operation of a given transformer?

Last Answer : a) Iron loss .........increases with a decrease in frequency. A 60-Hz transformer will have nearly 11% higher losses when worked on 50Hz instead of 60 Hz. However, when a 25-Hz ... ....since total loss is greater at a lower frequency, the temperature is increased with decrease in frequency.

Description : Does the transformer draw any current when its secondary is open?

Last Answer : Yes, no-load primary current.

Description : WHAT is ZIG ZAG Grounding Transformer

Last Answer : ANSWER: Three Single Phase Transformers can be connected to have a three phase Zig Zag Transformer. This system can be used for either grounding or developing a fourth WIRE from a three phase neutral. An example ... - three phase - three wire system to a 480Y/277 V - three phase - four wire system

Description : What is Meant by Temperature Rise in a Transformer?

Last Answer : ANSWER: Temperature rise in a transformer is the temper¬ature of the windings and insulation above the existing ambi¬ent or surrounding temperature, and is determined by the insulation class used in the transformer coils.

Description : What is Meant by Regulation in a Transformer?

Last Answer : ANSWER: Voltage regulation in transformers is the difference between the no load voltage and the full load voltage. This is usually expressed in terms of percentage. For example: A transformer delivers 100 ... from 2% to 4%, depending on the size and the application for which they are used

Description : What is Polarity, When Associated With a Transformer?

Last Answer : A: Polarity is the instantaneous voltage obtained from the primary winding in relation to the secondary winding. Transformers 600 volts and below are normally connected in additive polarity - that ... parallel for three phase operations. Polarity is a term used only with single phase transformers

Description : During No load why the power factor of the transformer is very low ?

Last Answer : A. Current flowing through the transformer consists of two components. Magnetizing current (Im) which is in quadrature (900) to the applied voltage and in phase current which is in phase to the applied voltage ... factor of transformer during no load condition will by in the order of 0.1 to 0.2

Description : Explain about auto transformer?

Last Answer : A. It is type of transformer with only one winding a portion of which is shared by both primary and secondary. Advantages: It is used where transformation ratio differs little from unity. As ... voltage as per out requirements and can smoothly increase or decrease its value as per our requirement.

Description : Explain about the open and short circuit tests on transformer?

Last Answer : A. Open circuit test (No load test) and short circuit test (full load test) are performed on a transformer to determine (i) Equivalent circuit of transformer (ii) Voltage ... determine copper loss in transformer at full load and parameters of approximate equivalent circuit of transformer.

Description : EMF equation of the transformer?

Last Answer : A. E = 4.44ΦmfN Volts. If E1 & E2 are primary and secondary emf’s and N1 & N2 are primary and secondary turns then, Voltage ratio= E1/E2 and Turns ratio of transformer = N1/N2 E1/E2 = N1/N2

Description : What is tertiary winding? What is Three Winding Transformer? What are its advantages?

Last Answer : A. In some high rating transformers, one winding, in addition to the primary and secondary winding, is used. This is known as Tertiary Winding of Transformer. Because of this third winding, the ... it assists in limitation of fault current in the event of a short circuit from line to neutral.