syllabus EMD-1 firest mid sem

1. GENERAL ASPECTS
Insulating Materials & Classifications, heating of electrical machines , Cooling
of Transformer and rotating machines , Electrical and Magnetic Loading ,
output coefficient , factor affecting size of machines , selection of B av & ac ,
Duty cycle and equivalent ratings
5
2. DESIGN OF THREE PHASE TRANSFORMER:
Types of transformers, position of HV and LV windings, core and yoke crosssectional
area, importance of mitered joints., Different types of transformers
windings. Different methods for cooling of transformer, Different positions of
tapings. Output equation for 3 phase transformers, window space factor,
factors affecting window space factor. Relation between emf per turn and
transformer rating, factors affecting constant K, stacking factor, examples.
Selection of flux density and current density, Window dimensions, Yoke
dimensions and overall core dimension calculations, examples. Design of HV
and LV windings (No. of turns and area of cross section). Estimation of
operating characteristics. Primary and secondary winding resistance. Leakage
reactance calculation of only cylindrical coil with equal height, Leakage
reactance of unequal windings and heights, only formula. No load current
calculations for 3 phase transformers. Temperature rise of transformer, design
of tank with tubes, calculation of dimension of tank, examples. Optimum
design Design for minimum cost. Design for minimum loss. Variation of
output and losses in transformer with linear dimensions. Dry transformer, high
frequency transformer

please refer only those questions which comes under above syllabus from following q-papers of GTU exams
Date:08 /05/2015
Date: 02/12/2014
Date: 03-06-2014
Date: 05-12-2013