Question
Question: The primary winding of a transformer has \(500\,\) turns where as its secondary has \(5000\) turns. ...
The primary winding of a transformer has 500 turns where as its secondary has 5000 turns. The primary is connected to an a.c. supply of 20V , 50Hz . The secondary will have an output of
(A) 2V,5Hz
(B) 20V,5Hz
(C) 200V,50Hz
(D) 20V,500Hz
Solution
Write the relation between the number of turns in the windings and the output voltage and substitute the known values in it. The simplification of the above term, gives the answer for the output voltage and the frequency of the secondary winding.
Useful formula:
The relation between the number of turns and the voltage of the transformer is given by
NPNs=VPVs
Where Ns is the number of turns of the secondary winding, NP is the number of turns of the primary winding, Vs is the voltage of the primary winding and VP is the voltage of the primary winding.
Complete step by step solution:
It is given that the
Number of turns in the primary winding of the transformer, NP=500
Number of turns in the secondary winding of the transformer, Ns=5000N
The voltage of the primary coil, Vp=20V
Using the relation of the transformer,
NPNs=VPVs
By rearranging the above equation and substituting the known values in the above step, we get
Vs20=5000500
By grouping the similar terms together,
Vs=50020×5000
By performing the basic arithmetic operation in the above step, we get
Vs=500100000
By simplifying the right hand side of the equation, we get
Vs=200V
The frequency of the windings are the same, and hence the secondary winding has the voltage output of 200V and the frequency of 50Hz .
Thus the option (C) is correct.
Note: The frequency is not influenced by the number of turns and it is the same for the primary and the secondary windings. The primary windings of the transformer collect the power from the battery and the secondary windings discharge the output voltage.