GTU BE 2019 Summer Question Papers || Gujarat Technological University
Subject Name: Electrical Machines
Time: 02:30 PM TO 05:00 PM Total Marks: 70
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER-III (NEW) EXAMINATION — SUMMER 2019
--- Content provided by FirstRanker.com ---
Subject Code: 2131005 Date: 18/06/2019Subject Name: Electrical Machines
Time: 02:30 PM TO 05:00 PM Total Marks: 70
Instructions:
- Attempt all questions.
- Make suitable assumptions wherever necessary.
- Figures to the right indicate full marks.
--- Content provided by FirstRanker.com ---
| Q.1 | MARKS | |
| (a) | Explain working principle and derive the emf equation of single phase transformer. | 03 |
| (b) | Explain the main parts of a D.C. machine with neat diagram. | 04 |
| (c) | Explain different types of D C Generator according to its field winding. | 07 |
| Q.2 | ||
| (a) | What is load factor, diversity factor and plant utilization factor? | 03 |
| (b) | Explain power factor. How can we improve power factor? | 04 |
| (c) | Explain open circuit and short circuit test on single phase transformer. | 07 |
| OR | ||
| (c) | What is regulation of alternator. Explain ZPF method for finding regulation in alternator. | 07 |
| Q.3 | ||
| (a) | Explain the losses of transformer. How these losses are reduce? | 03 |
| (b) | What is need of starter in DC machine? Explain construction and working of three point starter. | 04 |
| (c) | What is slip in induction motor? Explain torque/slip characteristics of induction motor. | 07 |
| OR | ||
| Q.3 | ||
| (a) | Explain equipments used in a substation. | 03 |
| (b) | What is the role of damper winding in (i) synchronous generator and (ii) synchronous motor? | 04 |
| (c) | With help of phasor diagram explain the operation of practical transformer on load. | 07 |
| Q.4 | ||
| (a) | Give comparison of squirrel cage and wound rotor motors. | 03 |
| (b) | State types of single-phase induction motor and explain any one. | 04 |
| (c) | Write advantages and application of auto transformer. | 07 |
| OR | ||
| Q.4 | ||
| (a) | State advantages and disadvantages of hydro power plant. | 03 |
| (b) | Explain the working principle of synchronous motor and state the methods of starting of synchronous motor. | 04 |
| (c) | Explain scott connection in transformer. | 07 |
| Q.5 | ||
| (a) | Explain any one of them. | 03 |
| (b) | Explain the Swinburne’s test of a d.c. machine | 04 |
| (c) | Explain equivalent circuit of the single phase transformer. | 07 |
| OR | ||
| Q.5 | ||
| (a) | Draw and explain the internal & external characteristics of d.c. shunt generators. | 03 |
| (b) | Explain armature reaction of the d.c. machine. Give its remedies also. | 04 |
| (c) | Explain three phase four wire and three phase three wire AC system and merits of each. | 07 |
--- Content provided by FirstRanker.com ---
This download link is referred from the post: GTU BE 2019 Summer Question Papers || Gujarat Technological University