HGCE ELECTRICAL : March 2016

ASSIGNMENT

State the main requirements for an ideal traction system. Give merits and demerits of electric traction over steam engine traction. Also explain the chief requirement of electric motors used for traction work.
Using the simplified trapezoidal speed time curve, derive an expression for themaximum speed in km/h in terms of acceleration, retardation, distance between stops and actual time of run between stops.
Draw typical speed-time curve for train movement and explain (a)acceleration (b) free running (c) coasting (d) retardation (e)Crest speed, (f)Average speed and (g)Schedule speed.
Discuss track electrification in detail & Compare AC and DC traction system.
Explain the method of series-parallel starting of traction motor. Mention its advantages
Draw a diagram of AC electric locomotive and explain function of each part in it
State various types of current collectors in common use for over head contact system. Describe with a neat diagram the pantograph collector.

Explain temperature rise of electrical drives with necessary expression.
What do you understand by load equalization? Derive the expression for Instantaneous motor torque, MOI of the flywheel and the motor slip. State the assumptions made if any.

Derive an expression for temperature rise of an electric motor
State the types of electric braking. Explain rheostatic & regenerative braking used in DC Motor
What do you mean by electric drive? What are the various factors which decide the choice of an electric drive for industrial application? Illustrate with example. Give classification of electric drive.
State with reasons the type of motor suitable for the following: (1) washing machine (2) grinding machine (3) belt conveyer (4) crane and hoist (5)electric traction (6) air conditioner (7) rolling mill (8)Pump (9) Blower (10)Hoist (11)Excavator (12) lathe (13)cement kiln

Explain faraday’s laws of electrolysis Also state its applications. Also explain current efficiency and energy efficiency

Define the terms: (1) Luminous intensity (2) Luminous efficiency (3) Utilization factor (4) Reduction factor (5) Reflection factor (6) candle power (7) Glare (8) Lux (9) MHCP(10) lamp efficiency (11)solid angle.