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

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
by

1 Answer

Answer :

C. By the flux
by

Related questions

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In a transformer the energy is conveyed from primary to secondary?

Description : In a transformer the energy is conveyed from primary to secondary?

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52 A transformer has 1000 primary turns, connected to 250V ac supply. To get 400V secondary voltage the no of secondary turns should be A. 1600 B. 250 C. 400 D. 1250

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50 The equivalent resistance of the primary of the transformer having K = 5, R1 = 0.1 ohm when referred to secondary becomes .....ohm A. 0.5 B. 0.02 C. 0.004 D. 2.5

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29. In transformer terminology, the ratio 20:1 indicates that A. there are 20 turns on primary one turn on secondary B. secondary voltage is 1/20th of the primary C. primary current is 20 times greater than the secondary current D. for every 0 turns on primary, there is one turn on secondary

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During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

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During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

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A certain transformer has 200 turns in the primary winding, 50 turns in the secondary winding and 120 volts

Description : A certain transformer has 200 turns in the primary winding, 50 turns in the secondary winding and 120 volts applied to the primary. What is the voltage across the secondary?  (A) 30 Volts (B) 480 Volts (C) 120 Volts (D) 60 Volts

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An ideal transformer has infinite values of primary and secondary inductances. The statement is?

Last Answer : An ideal transformer has infinite values of primary and secondary inductances. The statement is false.

In a transformer the resistance between its primary and secondary should be?

Description : In a transformer the resistance between its primary and secondary should be?

Last Answer : In a transformer the resistance between its primary and secondary should be infinity.

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

Description : 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

Last Answer : B. Absorbing moisture

Greater the secondary leakage flux?

Last Answer : Greater the secondary leakage flux less will be the secondary induced e.m.f.

68 The path of a magnetic flux in a transformer should have A. High resistance B. High reluctance C. Low resistance D. Low reluctance

Description : 68 The path of a magnetic flux in a transformer should have A. High resistance B. High reluctance C. Low resistance D. Low reluctance

Last Answer : D. Low reluctance

[53] The iron loss of the transformer is negligible during short circuit test because A. The entire input is just sufficient to meet Cu losses only B. Flux produced is a small fraction of the normal flux C. Iron core becomes fully saturated D. Supply frequency is held constant

Description : [53] The iron loss of the transformer is negligible during short circuit test because A. The entire input is just sufficient to meet Cu losses only B. Flux produced is a small fraction of the normal flux C. Iron core becomes fully saturated D. Supply frequency is held constant

Last Answer : B. Flux produced is a small fraction of the normal flux

27] In a transformer, the leakage flux of each winding is proportional to the current in that winding because A. Ohm's law applies to magnetic circuits B. Leakage paths do no saturate C. the two windings are electrically isolated D. mutual flux is confined to the core

Description : 27] In a transformer, the leakage flux of each winding is proportional to the current in that winding because A. Ohm's law applies to magnetic circuits B. Leakage paths do no saturate C. the two windings are electrically isolated D. mutual flux is confined to the core

Last Answer : B. Leakage path do not saturate

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Description : 6 The value of flux involved in the emf equation of a transformer is A. rms value B. rms value C. Maximum value D. Instantaneous value

Last Answer : C) maximum value

The use of higher flux density in the transformer design?

Last Answer : The use of higher flux density in the transformer design reduces weight per kVA.

The leakage flux in a transformer depends upon?

Last Answer : The leakage flux in a transformer depends upon load current.

The value of flux involved in the e.m.f. equation of a transformer is ?

Last Answer : Power on primary and secondary side of transformer A. Remains Approximately constant B. Are always different C. Is always 100kVA D. None of these

The path of magnetic flux in a transformer should have?

Description : The path of magnetic flux in a transformer should have?

Last Answer : The path of magnetic flux in a transformer should have low reluctance.

Why transformer oil is used as a cooling medium?

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.

D. Loading of the transformers not i76 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

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

An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to

Description :  An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to secondary turn’s ratio 12:1. The peak inverse voltage is A) 8.62 V B) 12 V C) 19.17 V D) 27.11 V 

Last Answer :  An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to secondary turn’s ratio 12:1. The peak inverse voltage is A) 8.62 V B) 12 V C) 19.17 V D) 27.11 V 

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

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

Last Answer : Yes, no-load primary current.

Does the transformer draw any current when secondary is open ? Why ?

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

Last Answer : Yes,it (primary) will draw the current from the main supply in order to magnetize the core and to supply iron and copper losses on no load . There will not be any current in the secondary since secondary is open

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

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

Increasing the number of turns of wire on the secondary of a transformer will

Description : Increasing the number of turns of wire on the secondary of a transformer will  (A) Decrease the secondary current (B) Increase the primary current (C) Have no effect on the secondary current (D) Increase the secondary current

Last Answer : Increasing the number of turns of wire on the secondary of a transformer will Decrease the secondary current 

When secondary of a current transformer is open-circuited its iron core will be?

Description : When secondary of a current transformer is open-circuited its iron core will be?

Last Answer : When secondary of a current transformer is open-circuited its iron core will be hot because of heavy iron losses taking place in it due to high flux density.

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

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.

Why to calculate equivalent impedance referred to primary or secondary side?

Description : Why to calculate equivalent impedance referred to primary or secondary side?

Last Answer : Equivalent impedance is essential to be calculated because the electrical power transformer is an electric power system equipment, for estimating different parameters of electric power system ... referred to primary or equivalent circuit of transformer referred to secondary sides respectively.

21.The ordinary two winding transformer's primary and secondary windings always have A. different no of turns B. same size of copper wire C. a common magnetic circuit D. separate magnetic circuits

Description : 21.The ordinary two winding transformer's primary and secondary windings always have A. different no of turns B. same size of copper wire C. a common magnetic circuit D. separate magnetic circuits

Last Answer : C. A common magnetic circuit

What will happen if DC supply is given on the primary of a transformer?

Description : What will happen if DC supply is given on the primary of a transformer?

Last Answer : A. Mainly transformer has high inductance and low resistance. In case of DC supply there is no inductance, only resistance will act in the electrical circuit. So, high electrical current will flow through primary side of the transformer. Due to this the coil and insulation will burn out.

What will happen if the primary of a transformer is connected to D.C. supply?

Description : What will happen if the primary of a transformer is connected to D.C. supply?  (A) Transformer will operate with low efficiency (B) Transformer will operate with high efficiency (C) No effect (D) Transformer may start to smoke and burn 

Last Answer : What will happen if the primary of a transformer is connected to D.C. supply?  (A) Transformer will operate with low efficiency (B) Transformer will operate with high efficiency (C) No effect (D) Transformer may start to smoke and burn 

A 230 V/460 V single-phase transformer operating at 20 A and unity power factor has primary referred

Description : A 230 V/460 V single-phase transformer operating at 20 A and unity power factor has primary referred resistance of 0.2 Ω and reactance of 0.5 Ω. The approximate primary induced emf is (A) 216 V (B) 226 V (C) 234 V (D) 236 V

Last Answer : A 230 V/460 V single-phase transformer operating at 20 A and unity power factor has primary referred resistance of 0.2 Ω and reactance of 0.5 Ω. The approximate primary induced emf is 226 V

Primary winding of a transformer?

Last Answer : Primary winding of a transformer could either be a low voltage or high voltage winding.

When a transformer is used to step down voltage, the low voltage winding is _____________. A. part of the core B. the primary coil C. not insulated D. the secondary coil

Description : When a transformer is used to step down voltage, the low voltage winding is _____________. A. part of the core B. the primary coil C. not insulated D. the secondary coil

Last Answer : Answer: D

If a transformer is connected to a DC source, the transformer will overload at the ____________. A. contacts B. primary coil C. secondary coil D. core

Description : If a transformer is connected to a DC source, the transformer will overload at the ____________. A. contacts B. primary coil C. secondary coil D. core

Last Answer : Answer: B

The secondary coil of a transformer in which the voltage is stepped down are usually made of thicker wire than primary. Why?

Description : The secondary coil of a transformer in which the voltage is stepped down are usually made of thicker wire than primary. Why?

Last Answer : The secondary coil is made of thicker wire to sustain larger electric current.

What are primary and secondary coil in a transformer?

Description : What are primary and secondary coil in a transformer?

Last Answer : The coil which is connected to input source is called primary coil. The coil which is connected to the output source is called secondary coil.

Turn ratio of a transformer is 5. If 220 V AC is applied to its primary coil, voltage in the secondary coil will be: a. 44V b. 4.4 V c. 220V d. 1100V

Description : Turn ratio of a transformer is 5. If 220 V AC is applied to its primary coil, voltage in the secondary coil will be: a. 44V b. 4.4 V c. 220V d. 1100V

Last Answer : c. 220V

The primary coil of a transformer is connected to a 60 V ac source. The secondary coil is connected to a 330

Description : The primary coil of a transformer is connected to a 60 V ac source. The secondary coil is connected to a 330 ohms load. The turns ratio is 3:1. What is the secondary voltage? A.2 V B.20 V C.180 V D.18 V

Last Answer : The primary coil of a transformer is connected to a 60 V ac source. The secondary coil is connected to a 330 ohms load. The turns ratio is 3:1. What is the secondary voltage? A.2 V B.20 V C.180 V D.18 V