Utilization of Electrical Energy and Traction. UTU (uttrakhand technical university previous year question papers)

B.tech question papers
sub- Utilization of Electrical Energy and Traction.
UTU (uttrakhand technical university
previous year question papers)
Dec 2014

Q1: Attempt any four:

1. What are the advantages of induction heating? Give classification of various heating methods.
2. What is Ajax-Wyatt Furnace? Describe construction, principle of operation and application of this furnace.
3. Discuss advantages of electrically produced heat. State the properties of a heating element used for this heating.
4. Explain with help of neat sketch the working of Ajax Wyatt furnace.
5. A 40KW 3 phase 400v, resistance oven is to employ nichrome strip 0.25mm thick for the three star-connected heating elements. If the wire temperature is to be 1200C and that of the charge is to be 800C, estimate a suitable width for the strip. Assume emissivity= 0.9 and radiating efficiency=0.5. Also determine the temperature of the wire when the charge is cold.
6. What are the factors which limit the choice of frequency in induction and dielectric heating?

Q2: Attempt any four:

1. Name and describe various resistance welding processes.
2. Discuss the principle of arc welding and the difference between carbon and metallic arc welding and their relative merits.
3. Write the difference between seam welding and flash butt welding.
4. State Faraday's laws of electrolysis.
5. Describe the process of extraction of metals.Explain how zinc and aluminum are extracted from their ores.
6. Explain shielded metal arc welding with the help of neat diagram.

Q3: Attempt any two:

1. a) What is law of illumination? Find expression for illumination due to circular disc.
   b) Write short note note on 1) Luminous Intensity 2) Candle power 3) Brightness.
2. Explain with neat diagram the principle of thermo-electric refrigeration system also give its merits and demerits.
3. With the help of neat diagram explain air conditioner. Give the names of refrigerants used and explain non-cyclic refrigeration system.

Q4: Attempt any two:

1. Draw the speed-time curve for urban, suburban and main line services and also explain why free running time is reduced in urban and suburban services?
2. The distance between two stations is 1.92kms. The schedule speed and the duration of the stops respectively are 40kmph and 20 sec, assume the quadrilateral approximation of the speed-time curve and the coasting and braking retardation as 0.16kmphps. and 3.2kmph respectively. Determine the acceleration if the speed at end of the acceleration period is 60.8kmph. Also determine the duration of the coasting period.
3. Explain how and actual speed-time curve for an electric train service can be replaced by a curve having a simple geometric shape.Assume a simplified, speed-time curve derive the relationship between acceleration, retardation, maximum speed, running time and the distance between stops.

Q5: Attempt any two:

1. Explain the principle of operation of single phase ac series motor.Compare its performance with dc series motor when used for traction purposes.
2. What are the requirements of electric drive for traction? Explain a static control scheme used in a.c. traction employing a.c. motors.
3. Explain with the help of neat diagram shunt and bridge transitions used in case of series-parallel control of series motor. Which among them is preferable and why?

B.tech Examination papers dec 2014 sub - Switchgear and protection uttarakhand technical university previous year question papers uttarakhand technical university last year question papers utu previous year question papers on step4success