4 GRAPHITE electrodes are used in arc furnaces 1 R Duration: 1½ hours Max. Marks: 40 Part- A Objective Questions (10X1=10 Marks) 1 U 1 R

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1 Dr. Mahalingam College of Engineering and Technology, Pollachi-3 (An Autonomous Institution affiliated to Anna University) C C E T I 2 011/ R e g u l a t i o n ) Course Code & Course Title: 11EE702 Electric Energy Utilization Name of Programme: B.E. - EEE law of illumination (C) Bunsen's law of illumination cosine law. (D) Lambert's Sem: VII Date& Session: (FN1) 4 GRAPHITE electrodes are used in arc furnaces Duration: 1½ hours Max. Marks: 40 Part- A Objective Questions (10X1=10 Marks) 5 High striking voltage is required for ARC welding Radiant efficiency of the luminous source depends on (A) shape of the source (B) temperature of the source 1 CO Blooms No Level 6 Overall efficiency of steam locomotive system is close to (A) 5 to 10% (B) 25 to 30% (C) 55 to 60% (D) 75 to 80%. (C) wavelength of light rays above. (D) all of the The pressure of steam in a locomotive is (A) kg/cm 2 (B) Candela is the unit of 7 kg/cm 2 2 (A) Luminous flux intensity (B) Luminous (C) kg/cm 2 (D) kg/cm 2. (C) Wavelength above. (D) None of the In a steam locomotive electric power is provided through (A) battery system (B) diesel 3 The illumination is directly proportional to the cosine of the angle made by the normal to the illuminated surface with the direction of the incident flux. Above statement is associated with 8 engine generator (C) overhead wire turbo generator. (D) small (A) Planck's law (B) Macbeth's

2 9 Long distance railways use (A) 200 V DC Single phase AC (C) 25 kv Two phase AC phase AC. (B) 25 kv (D) 25 kv Three 100 times per second. Due to the persistence of vision, the human eyes do not recognize that extinguish. If such light falls on any moving object, because of extinguishing nature of lamp, the object appearing to be either running slow or fast or running in reverse direction, sometimes it may appear as stationary. This effect is called stroboscopic effect. Which locomotive has the highest operational availability (A) Diesel (B) Electric 10 (C) Steam (D) All have same availability. Part- B Short Answer Questions (5X2=10 Marks) 14 Identify the factors affecting energy consumption? The various factors affecting energy consumption are (i) Distance between the stops: (ii) Train resistance: (iii) Acceleration and retardation: (iv) Gradient: (v) Train equipment: CO No Blooms Level List the Requirements of ideal traction system? 11 Define Solid angle. A solid angle (symbol: Ω) is the two-dimensional angle in three-dimensional space that an object subtends at a point 15 The requirements of an ideal traction system are as follows The starting tractive effort should be high so as to haverapid acceleration. The wear on the track should be minimum. Pollution free 12 Define candle power? It is defined as the number of lumens given out by the source in a unit solid angle in a given direction. It is denoted by CP. CP=lumens Part- C Descriptive either or questions (2X10=20 Marks) CO Blooms No Level (i) Interpret the welding transformer and its 13 Discuss about stroboscopic effect in fluorescent tubes? The alternating nature of the supply goes through zero twice per a cycle. At the usual alternating current supply frequency of 50 Hz, the discharge lamp will be extinguished 16. (a) characteristics (4) Step down transformer-provide low voltage power for welding with some means of output control Here difference in voltage is absorbed by reactor

3 Reactor- helps in stabilizing the arc on account of low power factor which is nearly 0.35 lagging The open circuit voltage ranges from volts Control is obtained by regulating regulators Control of current flow in welding transformer Tapped reactor method Continuously variable reactor method Suitable reactor method (ii) Elucidate induction heating (6) 16. (b) OR A hall 20 m long and 15 m wide is to be illuminated and illumination required is 55 m. candles. Calculate the number, the voltage of each unit and the location and mounting height of the units taking a depreciation factor of 1.3 and utilization co-efficient of 0.5 given that the outputs of the different types of lamps are as below: Watts Ap

4 Lumens : Total lumens = Gross lumens = No of lamps = 28 Space height ratio = (a) Describe about the different supply systems for electric traction Four types: 1. DC system 600V, 750 V, 1500 V, 3000 V 2. 1ф AC system 15 to 25 KV, 16 2/3, 25, 50 Hz 3. 3ф AC system 3.3 to 3.6 KV at 16 2/3 Hz 4. Composite system involving conversion of 1ф AC to 3ф AC or DC DC system: For main lines operating at higher voltages of V are placed at km distance This high voltages 3ф supply at these substations is converted into low voltage 1ф supply with the help of Scott connected or V connected 3ф transformers Then these substations are converted to required DC voltage by suitable rectifiers or converters These substations are usually automatic & remote controlled AC system: 17. OR (i) Explain the mechanics of train movement (7)

5 (b) Note: Code for Blooms Levels: Sl. No. Blooms Level Code emember R nderstand U 3 Apply Ap 4 Analyze An 5 Evaluate E 6 Create C (ii) Briefly define tractive effort? (3) The effective force necessary to propel the train at the wheels of thelocomotive to which the motor is geared is called the geared effort/tractive effort. It ismeasured in Newtons and is tangential to the driving wheels. Total tractive effort required to run a train on track = Tractive effort to produce acceleration +Tractive effort to overcome effect of gravity +Tractive effort to overcome train resistance.