1)(a) Write down the difference and similarities between magnetic and electric circuit.
(b) The iron rod 1.8 cm diameter is bent to form ring of mean diameter 25cm and wound with 250 turns of wire a gap of 1mm exists in between end faces. Compute current required to produce a flux of 0.6mWb take relative permeability of iron as 1200
2)(a) Describe the two various types of magnetic circuits with neat and suitable diagram.
(b) When two coils are connected in series, their effective inductance is found to be 10H .When connections of one coil are reversed , effective inductance is 6H.If the coefficient of coupling is 0. 6, compute the self inductance of each coil and the mutual inductance.
3) What are the difference between core and shell type transformers.
4) Explain the purpose of laminating the core in a transformer.
5) Write down the emf equation of transformer and define each term.
6) Does transformer draw any current when secondary is open? Describe why?
7) Explain voltage regulation of transformer in detail.
8) Full load copper loss in the transformer is 1600W. Determine will be the loss at half load?
9) Describe all day efficiency of a transformer in detail.
10) Describe why transformers are rated in kVA?
11) Write down the typical uses of auto transformer.
12) Write down the application of step-up and step-down transformer.