Anna University, Chennai Nov/Dec 2012 Examinations
Rejinpaul.com Important Questions
EC2201/ Electrical Engineering
III Sem EEE
1. Explain the construction and working of three point starter?
2. Explain in detail about swimburne�s test?
3. Describe with a neat diagram the constructional features of DC machines
4. When running on no- load, a 400 V shunt motor takes 5 A. Armature resistance is 0.5 O and field resistance 200 O. Find the output of the motor and efficiency when running on full � load and taking a current of 50 A. Also find the % change in speed from no � load to full � load
5. Explain Torque speed characteristics of d.c shunt and d.c series motor with relevant derivations to justify their shape
6. Explain the principle of operation of a single phase transformer
7. A 5 KVA, 400/200 V 50Hz, single phase transformer gave the following readings.
OC: 400V, 1A, 50W (LV side opened)
SC: 12V, 10A, 40W (LV shorted)
Determine (i) Efficiency on full load 0.8 lagging power factor, (ii) regulation at 0.8 p.f lagging, (iii) Efficiency on 60% of full load 0.8 leading power factor ,(iv) Draw the equivalent circuit referred to primary and insert all the values
8. Discuss in detail with neat diagrams the constructional details of a transformer.
9. Determine the regulation of a transformer for resistive, inductive and capacitive loaded conditions
10.Derive the condition for maximum torque and also the expression for maximum torque
11.While delivering a useful power of 24 kW to the full load, a 3?, 50Hz, 8 Pole induction motor draws a line current of 57 A. It runs at a speed of 720 rpm and is connected to 415 supply. The p.f of the motor is 0.707 lagging. Stator resistance per phase is 0.1 O. The mechanical losses are 1000W.Calculate (i) Shaft torque(ii) Gross torque (iii) rotor copper loss (iv) stator iron loss (v) stator copper loss (vi) overall efficiency(vii) draw the power flow diagram
12.What are the methods of speed control in 3? induction motor? Explain them in detail
13.Explain the torque slip characteristics of 3? induction motor in detail
14.Explain in detail the MMF method of obtaining regulation of an alternator
15.Write detailed notes on (i) reluctance motor (ii) stepper motor
16.Explain the construction of two types of synchronous generator
17.Explain the construction and operation of hysteresis motor
18.Describe the types of DC links
19.Discuss about the types of cables used in power systems
20. Draw the schematic diagram of a electric power system. Briefly explain the structure
21.Explain in detail (i) Pin type insulator (ii) Pole mounted substation