Transformer Short Question Answer In English

1. What is a transformer and how does it work? 

Answer- A transformer is an electrical device that is converted from one voltage to another for alternating current. It can be designed for 'step up' or 'step down' voltage on the magnetic induction principle. A transformer has no moving parts and is a fully stationary solid state device, insuring under normal operating conditions, long and trouble-free life. It consists of the simplest form of two or more coils of insulated wire wound on a laminated steel piece. When the voltage is introduced to a coil, called the primary, it magnetizes the iron core. A voltage is then induced in another coil, called a secondary or output coil. The change of voltage (or voltage ratio) between the primary and secondary depends on the winding ratio of the two coils.

2. What are the conditions to be met for parallel operation of    transformers?

Answer - Parallel operation of Transformers - Before two transformers are introduced in parallel, the following conditions must be met. Two transformers must be in
(i)   Same phase Sequence. 
(ii)   Equal voltage ratio
(iii)  Equal polarity. 
(iv)  Equal per unit impedance ie same X / R ratio. 

3. What is voltage regulation in a transformer? 

Answer - The voltage regulation is defined as the change in the magnitude of receiving and sending voltage of the transformer. The voltage regulation determines the ability of the transformer to provide the constant voltage for variable loads
Voltage Regulation  % = ((V_NL - V_FL)/ V_FL)  x 100
Here is-
V_NL-No Load Voltage In volt
V_FL-Full Load Voltage In volt

4. Why is the neutral point of a transformer earthed? 

Answer - The transformer secondary winding’s neutral point is earthed.  Its benefits are as follows-
(i)   The load on the transformer remains balanced.
(ii)  Single-phase supply can be obtained. 
(iii)  Line testing can be done easily. 
(iv) Protects the human life to electric shock caused by them.

5.  What is the function of a transformer breather ?

Answer -Transformer oil is used for distribution and cooling of windings in power transformers.  The oil is filled in a tank with a small tank attached to it which is called a conservator.  When the oil cools and shrinks, the air of the atmosphere enters the conservator to fill the empty space.  Breather is used to absorb the moisture of this air.

6. What is the function of a transformer in a power system?

Answer - Transformer - Transformer is a static device, which is AC  Is transferred from one circuit to another.  In power system, the transmission of electric power is done at high voltage and the distribution work is done at low voltage (440V).  Hence the step-up transformer is used to raise the voltage at the generating station and to lower the voltage at the distribution centers.  (11000V / 400V) Step-down transformers are used at sub stations.

7. What is No load losses in a transformer. 

Answer - No load loss in a transformer - Zero - load is only 2% to 5% of its full - load value.  This electric current produces a magnetic field at the core and carries iron losses.  Iron losses consists of
(a) Eddy current  losses and
(b) Hysteresis losses.  

8. What is Auto Transformer

Answer - Auto Transformer - This type of transformer has only one winding, whose entire winding works for primary and some part for secondary.  At this time it is called step down.  If some part of the coil works as primary and the whole winding secondary, then it acts like a step up transformer.  It is used in voltage stabilizer, voltage variation of motor etc.

9. What Are Current Transformer?

Answer -They are protective devices used to measure very high value of current in  power system. The Current Transformer ( C.T. ), is a type of instrument transformer that is designed to produce an alternating current in its secondary winding which is proportional to the current being measured in its primary.

10.  What Are Potential Transformer?

Answer -The potential transformer may be defined as an instrument transformer used for the transformation of voltage from a higher value to the lower value. This transformer step down the voltage to a safe limit value which can be easily measured by the ordinary low voltage instrument like a voltmeter, watt meter and watt-hour meters, etc.