Name of the College : Dr T Thimmaiah Institute of Technology
University : Visvesvaraya Technological University
Department : Mining Engineering
Degree : B.E
Subject Code/Name : 10MN32/Mining Electrical Engineering
Sem : III
Year : Dec.2013/Jan.2014
Website : drttit.gvet.edu.in
Document Type : Question Paper
Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/drttit.gvet.edu.in/5851-10MN32%20Dec13.pdf
Mining Electrical Engineering Question :
Third Semester B.E. Degree Examination, Dec.2013/Jan.2014 :
Time: 3 hrs.
Max. Marks: 100
Related : Dr T Thimmaiah Institute of Technology 10MN33 Mining Geology-I B.E Question Paper : www.pdfquestion.in/5850.html
Note:
Answer FIVE full questions, selecting at least TWO questions from each part.
PART-A :
a. Mention any five Indian Electricity rules and application to Mining Industry. (05 Marks)
b. Define the terms related to mine illumination. Mention the importance of electrical engineering in mining. (10 Marks)
c. Write short notes on :
i) Voltage limits; ii) Disconnection of supply. According to the Indian Electricity rules 1956. (05 Marks)
2 a. What is an electric drive? Explain with a block diagram. (07 Marks)
b. What are the main factors which decide the choice of electric drive? (07 Marks)
c. List out the difference between AC. drives and D.C. drives. (06 Marks)
3 a. With a neat sketch of a coal mine shaft, explain the electric winder system in mines. (08 Marks)
b. Compare AC. mine hoists and D.C. mine hoists. (04 Marks)
c. Explain various types of shears used in long wall mining method in underground mining operation. (08 Marks)
4 a. Explain the electric braking of D.C. motors and AC. motors as per Electrical Rule 1956. (12 Marks)
b. A 500 V shunt motor runs at its normal speed of250 rpm and the armature current is 200 A. The resistance of the armature is 0.120. Calculate the speed when a resistance is inserted in the field reducing the shunt field to 80% of normal value and the armature current is 100 A. (08 Marks)
PART-B :
5.a.Explain the Ward-Leonard method of speed disadvantages. (12 Marks)
b. Obtain the ratio of starting torque to full load torque. control. Also give their advantages and disadvantages (08 Marks)
6.a Explain with a neat sketch, the working principle of minimum oil circuit breaker. What are the advantages and disadvantages of it? (12 Marks)
b. Explain the principles of underground signaling system in the mines. (08 Marks)
7.a Explain underground power distribution. (08 Marks)
b. Distinguish between flame proof apparatus and intrinsically safe apparatus. (06 Marks)
c. Write short notes on underground cable. (06 Marks)
8.a.Explain the standards for mine lighting used in underground mines. (08 Marks)
Explain Luminance measurements used in mines. (04 Marks)
Write the design steps for lighting system in mines. (08 Marks)
Third Semester B.E. Degree Examination, June/July 2015 :
Mining Electrical Engineering :
Time : 3 hrs.
Max. Marks : 100
Note : Answer FIVE full questions, selecting at least TWO questions from each part.
PART-A :
1.a. Mention the Indian electricity rules applicable to mining Industry.
b. Explain the scope and importance of electrical engineering in mining.
2.a. What is an Electrical Drive? With general block diagram representation, Explain electrical driving system. (07 Marks)
b. What the factors that decide the choice of electrical drives? (07 Marks)
c. List out the differences between Ac drives and De drives. (06 Marks)
3. a. Compare AC mine hoists and DC mine hoists. (04 Marks)
b. Explain various types of shearers used in long wall mining method in under ground mining operation. (08 Marks)
c. With neat sketch of coal mine shaft, explain the electric winder system in mines. (08 Marks)
4. a. Explain Electric braking of AC and DC motors. (12 Marks)
b. A 230V DC shunt motor runs at 800 rpm and takes armature current of 50 A. Find the resistance to be added to field circuit to increase speed to 1000 rpm at an armature current of 80 A. Assume flux proportional to field current. Armature resistance = 0.150. field winding resistance = 2500. (08 Marks)
Part-B :
5.a. Explain ward-Leonard method of speed control of DC motor. (10 Marks)
b. A 200V, 200A, 800 rpm DC separately excited DC motor has an armature resistance of 0.060. the motor armature is fed from a variable voltage source with an internal resistance of 0.040.
Calculate internal voltage of the variable voltage source, when the motor is operating in regenerative braking at 80% of the rated motor torque and 600 rpm. (10 Marks)
6.a. What are circuit breker? How are they classified? Explain with neat sketch, principle of operation of Air Break circuit Breaker. (12 Marks)
b. Explain the principles of underground signaling system in mines. (08 Marks)
7. a. Distinguish between flame proof apparatus and intrinsically safe apparatus.
b. With schematic diagram, Explain power distribution in mines?
c. Write short notes on underground cables.
8 a. Explain the standards for mine lighting at different work places?
b. Write short notes on : i) Open cost and ii) Underground mines