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Which of the following is not available in transformer?
A) Breather
B) Conservator
C) Buchholz relay
D) Commutator
Commutator
A commutator is a mechanical rotary switch used in DC machines (DC generators and motors) to convert AC to DC or vice versa. A transformer is a static electromagnetic device with no moving or rotating parts, so a commutator is not present in it.
A commutator is a mechanical rotary switch used in DC machines (DC generators and motors) to convert AC to DC or vice versa. A transformer is a static electromagnetic device with no moving or rotating parts, so a commutator is not present in it.
E=4.44тЛЕfтЛЕNтЛЕ╬жmтАЛ тАФ EMF equation of a transformer
V2тАЛV1тАЛтАЛ=N2тАЛN1тАЛтАЛ=I1тАЛI2тАЛтАЛ=K тАФ Transformer transformation ratio
A transformer operates on the principle of mutual induction between two or more stationary windings linked by a common magnetic field. Since energy is transferred purely via electromagnetic induction without mechanical motion or direction-reversal of currents via physical contact, components like commutators or brushes are entirely absent.
A transformer is a static device that transfers electrical energy between circuits at a constant frequency.
Breather contains silica gel to absorb moisture from the air entering the conservator tank during thermal breathing.
Conservator tank provides space for the thermal expansion and contraction of transformer oil during temperature changes.
Buchholz relay is a gas-operated protective relay installed between the main tank and conservator to detect internal incipient faults.
Commutators are exclusive to rotating electrical machinery such as DC generators and DC motors.
Option A (Breather): Contains silica gel (cobalt chloride treated); absorbs moisture during air inhalation.
Option B (Conservator): An airtight auxiliary drum mounted above the main tank to handle oil volume expansion.
Option C (Buchholz Relay): Installed in the pipe connecting the main tank and conservator; triggers alarm/trip for internal faults.
Option D (Commutator): Used only in DC machines to collect current from armature conductors or reverse current directions mechanically.
D is correct тАФ A commutator is a mechanical component used only in rotating DC machines, whereas a transformer is a completely static device with no moving parts.
Always remember that transformers operate strictly on alternating current (AC) and mutual induction, requiring no mechanical commutators, slip rings, or brushes.