Utilization of Electrical Energy (UEE) Sample Question Paper I Scheme MSBTE Electrical Engineering Group

Q.1Attempt any Five of the following.
(10 Marks)

a) Define the following terms with reference to illumination
 i) MSCP
 ii) Coefficient of Utilization
b) State Lambert’s cosine law of illumination.
c) Write the classification of resistance welding.
d) Define group drive and individual drive.
e) List any four requirements of an ideal traction system.
f) Explain any four desirable characteristics of tariff.
g) List any four causes of low power factor.

Q.2Attempt any Three of the following.
(12 Marks)

a) Draw a neat labeled diagram of the conventional fluorescent tube light. State the
function of choke and starter in it.
b) Draw V-I characteristics of an electric arc. Describe how arc length affects the arc
stability.
c) Define mechanical power transmission system of electric drive. List out its types.
d) Describe any four advantages of 25 kV A.C. traction system.

Q.3) Attempt any Three of the following.
(12 Marks)

a) Describe the main features and areas of applications for
i) Semi-direct and ii) Indirect lighting schemes.
b) Explain with a neat labeled schematic diagram the working of the Ajax Wyatt furnace.
c) Explain with necessary circuit diagram, plugging applied to D.C. series motor.
d) Describe a tariff mainly used to prepare bill for i) L.T. Residential consumer ii) H.T.
Industrial consumer.

Q.4) Attempt any Three of the following.
(12 Marks)

a) List any four equipment’s used in arc furnace with their application.
b) Draw the curve and estimate suitable H.P. of motor having following duty cycle:
 1) Rising load from 200 to 400 H. P. - 4 minute
 2) Uniform load of 300 H.P. - 2 minute
 3) Regenerative braking from 50 to zero H.P. - 1 minute
 4) Idle for - 1 minute
c) Define i) Average speed and ii) Schedule speed in traction system. Write any two
factors affecting the schedule speed.
d) Compare electric locomotive over diesel locomotive on the basis of:
 (i) Centre of gravity,
 (ii) Running / maintenance cost,
 (iii) Starting time and
 (iv) Regenerative braking.
e) A 400 V, 50 Hz, 3-phase line delivers 200 kW at 0.7 p.f. lagging. It is desired to
improve the line power factor to unity by using shunt capacitors. Calculate value of
capacitance of each unit if they are connected in delta.

Q.5) Attempt any Two of the following.
(12 Marks)

a) A 40 kW, 3-phase, 400 V resistance oven uses nickel-chromium strip of 0.3 mm
thickness. The heating elements are star connected. The wire temperature is to be
1127°C and that of charge is to be 727°C, estimate the width and length of the wire
required.
Given: radiation efficiency = 0.6, specific resistance of Ni-Cr = 1.03×10–6 ohm-m,
emissivity = 0.9 .
b) i) Explain the factors on which shape and size of the elevator car depends.
ii) List any four safety and protective devices used in elevator.
c) A trapezoidal time curve of train consists of :
i) Uniform acceleration of 6 kmphps for 25 seconds
ii) Free running for 10 minutes
iii) Uniform deceleration of 6 kmphps to stop the train
iv) A stop time of 5 minutes.
Find the distance between the stations, average and scheduled speed.

Q.6) Attempt any Two of the following.
(12 Marks)

a) Compare A.C. welding with D.C. welding on the basis of:

1.  Equipment,
2.  Operating efficiency,
3.  Cost,
4.  No-load voltage,
5.  Heating and
6.  Arc stability

b) State the need of load equalization in motors. Describe the method to achieve it.
c) “DC series motor is used for traction purpose”. Justify