Question is ⇒ Delta/star transformer works satisfactorily when, Options are ⇒ (A) load is balanced only, (B) load is unbalanced only, (C) on balanced as well as unbalanced loads, (D) none of the above, (E) , Leave your comments or Download question paper.

Question is ⇒ Delta/star transformer works satisfactorily when, Options are ⇒ (A) load is balanced only, (B) load is unbalanced only, (C) on balanced as well as unbalanced loads, (D) none of the above, (E) , Leave your comments or Download question paper. Previous question Next question


Q1.	Delta/star transformer works satisfactorily when
A.	load is balanced only [Wrong Answer]
B.	load is unbalanced only [Wrong Answer]
C.	on balanced as well as unbalanced loads [Correct Answer]
D.	none of the above [Wrong Answer]
View Answer 10 -8 Explanation:- Answer : C Discuss it below : !! OOPS Login [Click here] is required to post your answer/result Help other students, write article, leave your comments

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Also Read Similar Questions Below :

⇒ Which of the following: statements about a transformer having a small short-circuit voltage is true ?
A low short-circuit current flows through the transformer
A high short-circuit current flows through the transformer
The transformer has high copper losses during the operation
The transformer has high iron losses during the operation

⇒ Which of the following does not change in an ordinary transformer ?
Frequency
Voltage
Current
Any of the above

⇒ The power transformer is a constant
voltage device
current device
power device
main flux device

⇒ Increase in secondary current of a transformer brings about increase in primary current. This is possible because
primary and secondary windings are capacitively coupled
primary and secondary windings are inductively coupled
primary and secondary windings are conductively coupled
none of the above

⇒ Leakage fluxes of a transformer may be minimized by
avoiding overloads
keeping magnetizing current to the minimum
reducing the reluctance of the iron core to the minimum
sectionalizing and interleaving the primary and secondary windings

⇒ When a delta connected prirnary of a 3-phase transformer is connected to 3- phase supply
magnetizing current in phase winding will carry third harmonics but line current vvill be free from it
magnetizing current in phase winding will contain third harmonics and line current will alsò contain third harmonics
magm.etizing current in phase winding will not contain third harmonics but line current will contain third harnionics
none of the above

⇒ Iron loss of a transformer can be measured by
low power factor wattmeter
unity power factor wattmeter
frequency meter
any type of wattmeter

⇒ The rating of a transformer is given in kVA instead of kW because
kVA is fixed whereas kW depends on load p.f.
load power factor is often not known
it has become customary
total transformer loss depends on VA

⇒ The chemical used in breather is
asbestos fibre
silica sand
sodium chloride
silica gel

⇒ The place of transformer installation is selected such that
location is not too warm
plenty of dry and clean air is available and wet conditions are not encountered
location is not subject to damage from men and material traffic
all above requirements are met, with

⇒ The yoke sections of transformers using hot-rolled laminations is made 15 per cent greater than that of the core so as to
to increase the size of the transformers
to reduce the copper loss
to reduce the iron loss in yoke and magnetizing current
to provide better cooling

⇒ In the transformer the function of a conservator is to
provide fresh air for cooling the transformer
supply cooling oil to transformer in time of need
protect the transformer from damage when oil expends due to heating
none of the above

⇒ Gas is usually not liberated due to dissociation of transformer oil unless the oil temperature exceeds
50°C
80°C
100°C
150°C

⇒ The maximum load that a power transformer can carry is limited by its
temperature rise
dielectric strength of oil
voltage ratio
copper loss

⇒ While rising and falling if a wave is not symmetrical, it contains
even harmonics in addition to fundamental
odd harmonics in addition to fundamental
both odd and even harmonics in addition to fundamental
none of the above

⇒ For power purpose sine wave shape is preferred because
it gives least copper losses
it is easy to generate e.m.f. of this wave shape
it is stable wave shape as the line parameters cannot change it
none of the above

⇒ The changes in volume of transformer cooling oil due to variation of atmospheric temperature during day and night is taken care of by which part of transformer
Conservator
Breather
Bushings
Buchholz relay

⇒ Delta-delta power transformer is protected by current transformer having
star/star connections
delta/delta connections
star/delta connections
delta/star connections

⇒ The transformer laminations are insulated from each other by
mica strip
thin coat of varnish
paper
any of the above

⇒ A transformer can have zero voltage regulation at
leading power factor
lagging power factor
unity power factor
zero power factor

⇒ In core-type transformers, the concentric windings are used with
low voltage winding placed next to core
low voltage winding on the outerside
high voltage winding placed next to core
high voltage winding on the outerside

⇒ A transformer transforms
voltage
current
current and voltage
power

⇒ The path of the magnetic flux in transformer should have
high reluctance
low reactance
high resistance
low resistance

⇒ All day efficiency is the ratio of output to input in
kVA at a particular instant
kW at particular instant
kVARh at particular instant
kWh during 24 hours

⇒ The secondary winding of which of the following transformers is always kept closed ?
Step-up transformer
Step-down transformer
Potential transformer
Current transformer

⇒ Which of the following will improve the mutual coupling between primary and secondary circuits ?
High reluctance magnetic core
Transformer oil of high breakdown voltage
Low reluctance magnetic core
Winding material of high resistivity

⇒ Two transformers operating in parallel will share the load depending upon their
leakage reactance
per unit impedance
efficiencies
ratings

⇒ The path of a magnetic flux in a transformer should have
high resistance
high reluctance
low resistance
low reluctance

⇒ In a transformer overcurrents affect
mechanical stress
temperature rise
insulation life
all of the above

⇒ Power transformers are generally designed to have maximum efficiency around
no-load
half-load
near full-load
10% overload