07A80201 Utilization of Electrical Energy B.Tech Question Paper : scce.ac.in
Name of the College : SREE CHAITANYA COLLEGE OF ENGINEERING
University : JNTUH
Department : ELECTRICAL AND ELECTRONICS ENGINEERING
Subject Code/Name : 07A80201/UTILIZATION OF ELECTRICAL ENERGY
Year/Sem : IV/II
Website : scce.ac.in
Document Type : Model Question Paper
Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/scce.ac.in/4929-07A80201-UTILIZATIONOFELECTRICALENERGY.pdf
SCCE Electrical Energy Question Paper
Code No: 07A80201
R07
IV B.Tech II Semester Examinations,April/May 2012
Related : Sree Chaitanya College Of Engineering 07A70206 High Voltage Engineering B.Tech Question Paper : www.pdfquestion.in/4925.html
Electrical & Electronics Engineering
Time: 3 hours
Max Marks: 80
Set No. 2
Answer any FIVE Questions :
All Questions carry equal marks :
1. What is rheostatic barking and what precautions are taken when rheostatic braking is applied to d.c series traction motor? [16]
2. (a) What are the various methods of electric welding?
(b) Describe the various types of electric Arc welding processes. [8+8]
3. (a) Discuss in detail the various light fittings used for indoor lighting giving special applications of each of them.
(b) What are the qualities required in the fittings meant for out door installation? [8+8]
4. Explain how an actual Speed-Time curve can be replaced by a curve having simple geometric shape. [16]
5. (a) State the inverse square law and cosine law.
(b) A lamp taking 3.5A at 100V emits 6000 lumens. Calculate its efficiency in
i. Lumens per watt
ii. Mean spherical candle power per W
iii. A lamp taking 0.5A and 250V is rated at 125 MHCP. Find its efficiency in
A. MHCP per watt
B. Lumens per watt. [8+4+4]
6. Draw the connection diagram of the equipment for automatically starting:
(a) A squirrel cage induction motor by means of an auto-transformer
(b) A slip ring induction motor by means of resistive in the rotor circuit. [8+8]
7. The distance between two stations is 1.92km. Scheduled speed and duration of stop is 40 kmph and 20 sec. Assume quadrilateral approximation of speed-Time curve and wasting and braking retardations as 0.16kmphps and 3.2kmphps respectively, the weight of the train as 200 tons, the accelerating weight is 1.1 times that of dead weight and train resistance during accelerating period as 4.53kg/ton,
determine
(a) Specific energy output of the run
(b) Energy dissipated in brakes
(c) Energy utilized during coasting
(d) The mean train resistance during coasting. [16]
8. (a) What are the characteristics of heating element? Explain the design of heating element is resistance heating.
(b) A 50KW, 3-phase, 440V resistance furnace is to employ nickel-chrome strip of 0.3 mm thick for star connected elements. The temperature of the strip is to be 1500 0C and that of charge 1000 0C. Find the length and width of the strip. Take e= 0.91 and K=0.6. [8+8]
Set No. 4
Code No: 07A80201
R07
1. Derive an expression for tractive eort for:
(a) Acceleration
(b) On a gradient
(c) Resistance. [16]
2. (a) Describe the construction and principle of working of an induction furnace.
(b) Determine the energy required to melt 500 kg of brass in 30 minutes. Assuming specific heat = 0.095, Latent heat of fusion of brass = 39 cals/kg. melting point of brass = 9200, furnace n=50%, temperature of cold charge = 200C. [8+8]
3. Discuss the application of rheostatic braking as applied to series and a.c induction motors with neat diagram. [16]
4. Explain the various factors to be taken into account for designing schemes of
(a) Flood lighting
(b) Highway lighting. [16]
5. With the help of a complete Speed-Time curve, discuss how dierent parameters of this curve change with the type of train service. [16]
6. (a) What are the various methods of welding?
(b) What are the advantages of coated electrodes in welding process? [16]
7. (a) What are polar curves as applied to light sources? Show how these curves are used for finding in MHCP and MSCP.
8. (a) Compare the 3-Phase induction motor and DC shunt motors from the point of view of ease of speed control.
(b) A 230V, dc shunt motor runs at 900 rev/min on no-load with full field and has an armature resistance of 0.7 ohms. The armature current to give full load torque is 15A. if a resistance of 6 ohms is put in series with the armature, determine the speed-torque characteristic. Also find the current drawn from the supply. [8+8]