Uttarakhand Technical University 2010-4th Sem B.Tech Mechanical Engineering Electrial Machine;- Question Paper

COLLEGE OF ENGINEERING ROORKEE
B.Tech(4th semester)-Mechanical Engineering

Note:Attempt all ques..
Every ques. contains three marks.

1.Explain sumpner's test for testing 2 single phase transformer.Also discuss why is it beneficial for finding efficiency of transformers.

2.What is an auto-transformer?State its merits and demerits over 2 winding transformer.Give the construction features and discuss the working principle of a single phase auto-transformer.

3.What are the advantages of a bank of a 3 single phase transformer over a unit 3 phase transformer group?

4.What are the distinguishing features of the subsequent connections:\
a)star-star
b)star-delta
c)delta-star
d)delta-delta

5.A 400/100V,5kva,two winding transformer is to be used as an auto-transformer to supply power at 400V from 500V voltage source.Draw the connection diagram and determine the kva output of the auto-transformer.

Earning:   Approval pending.