Utilization of Electrical Energy 2018 Question Paper — Government Col…
The 2018 Utilization of Electrical Energy previous year question paper (Government College of Engineering and Technology, Jammu), with every question and its marks.
- University: Government College of Engineering and Technology, Jammu
- Subject: Utilization of Electrical Energy
- Course: Electrical Utilization
- Branch: Electrical Engineering
- Year: 2018
- Paper: end-term
- Duration: 180 minutes
- Total marks: 100
Instructions
- Attempt five questions in all selecting at least two questions from each Section.
- Each question carries 20 marks.
- Assume any missing data suitably.
- Use of calculator is allowed.
Questions
SECTION - A
- Q1. a) Discuss the factors which affect the selection of motor for a particular drive. (10) b) What are the essential requirements for satisfactory braking? Compare the performance of electrical and mechanical braking. (10) [20 marks]
- Q2. a) Why is a D.C. series motor ideally suited for traction purposes? Explain (8) b) The distance between two stations is 1.6 km and the average speed of the train is 40 kmph. The acceleration, retardation during coasting and braking are 2 kmphps, 0.16 kmphs and 3.2 kmphps respectively. Assume quadrilateral approximation of speed time curve, determine the duration of the accelerating, coasting and braking periods and distance covered during these periods if the maximum speed is to be limited to 64 kmph. (12) [20 marks]
- Q3. a) State the characteristics desirable in motors for passenger lifts.What special features are incorporated in each motors. If both D.C. and A.C. supplies are available which type of motor will you prefer and why? (14) b) Write a short note on speed time curve. (6) [20 marks]
- Q4. a) Explain electric traction system and discuss its merits over other traction systems. (10) b) Define the term coefficient of adhesion and explain the factors on which it depends? (10) [20 marks]
SECTION -B
- Q5. a) What are different methods of electric heating? Describe briefly the methods of direct and indirect resistance heating. List the applications of these two methods. (10) b) What is dielectric heating? How is this different from induction heating? (10) [20 marks]
- Q6. a) Describe different methods of resistance welding. (12) b) Find the current per line in a 3 phase arc furnace to melt 5 metric tonne of steel in one hour at an overall efficiency of 50%. If the arc is 115V,. initial temperature 30°C, melting point of steel 1370°C. specific heat of steel 278 J/kg/°C, latent heat of steel is 37000 J/kg. (8) [20 marks]
- Q7. a) Explain various lighting scheme and indicate the various factors to be considered for designing a lighting scheme. (10) b) In a street lighting scheme, lamps having uniform C.P. of 500 are hung at a height of 6 metres. The distance between consecutive lamp posts is 8 metres. Find the illumination under lamps and at centre in between the lamp posts. (10) [20 marks]
- Q8. a) Explain in detail the principle of arc lamps. (10) b) Explain the working of Incandescent lamp. (10) [20 marks]