Synopsis of Electrical Engineering

Rate Analysis Item: Wiring for 6A (3 Pin) & 16 A (6 pin)socket outlet point  in heavy guage PVC casing with 4 Sq.mm wires & 4 Sq.mm insulated earth wire complete with switches & socket outlets in one box. A Short point up to 3 meters Sl.No Description Unit  Qty Rate (Rs) Amount (Rs) Remarks 1 Wiring with 3 ×4 Sq.mm single core copper cable in suface heavy guage PVC casing meter 3 188.3 564.93 DSR 2013 item No 1.12 +13.5% ×0.75% VAT (171+17.31=188.31) 2 200mm ×125mm×60mm metal box No 1 51.54 51.54 DSR 2013 item No 1311+13.5%×0.75% VAT(46.8+4.74=51.54) 3 3 mm thick phenolic laminated sheet sq.cm 250 0.1 25 Adopted from DSR 2013 item No 1322 + 13.5%×75% VAT (0.09+0.009=0.10) 4 Supplying & fixing 3 pin 5/6A socket outlet on existing  switch box including connection

Here, item specifications and their rates are given for " installation of exhaust fans in residential quarters". Assumptions made: 1. Exhaust fans of  Bajaj make, 50 HZ, 225/250 MM sweep, 240 V AC  are supplied separately. 2. No provision is available to install exhaust fan in kitchen. 3. Total number of fans to be installed are of 29 Nos. with the above assumptions, the specifications and item rates for the above work are as given below: Sl. No. Description of item Unit Quantity Rate (Rs.) Amount (Rs.) 1 Installation & Commissioning  of light duty exhaust fan , Bajaj make, 50 HZ, 225/250 MM sweep, 240 V AC operated complete with suitable wooden supporting frame , fan blades, nuts and bolts, fan regulator, capacitor, 6A 3 pin plug top for terminals of exhaust fan and all other accessories and bird proof net with 24mm×21mm mesh size &14SWG wire in a wooden structure outside exhaust fan opening includin

1.        When a pumped storage power plant is operated in conjunction with a steam power plant a.        The operating cost of the steam plant becomes optimum b.       Load factor of the steam plant is increased c.        Chances of the tripping of the system decreases because of the use of two heterogeneous types of plants d.       Operation of the storage plant in the pumping mode during the low-load period improves the steam-plant stability 2.        Usage of materials in components of a nuclear reactor:     Graphite is used in moderators;   Boron is used in control rods ;   Sodium is used as a coolant ;  Concrete is used as a shield 3.        A 100km long transmission line is loaded at 110kV. If the loss of line is 15MW and the load is 150MVA, the resistance of the line is a.        8.06 ohms per phase b.       0.806 ohms per phase c.        0.0806 ohm per phase d.       80.6 ohms per phase 4.        Two insulator discs of identical capacitance value C ma

Important Multiple Choice Questions on Electrical Machines 1.        Can a 50Hz transformer be used for a 25Hz if the input voltage is maintained constant at the rated value corresponding to 50Hz? a)       Yes. Since the voltage is constant, current levels will not change. b)       No. Flux will be doubled which will drive the core excessive saturation. c)        No. Owing to decreased reactance of transformer, input current will be doubled at load. d)       Yes. At constant voltage, insulation will not be overstressed. 2.        In a transformer, if the iron losses and copper losses are 40.5 kW and 50 kW respectively, then at what fraction of load will be the efficiency be maximum? a)       0.8 b)       0.57 c)        0.7 d)       0.9 3.        If the frequency of input voltage of the transformer is increased keeping the magnitude of voltage unchanged, then a)       Both the hysteresis and eddy current losses in the core will increase. b)       Hysteresis l

Important multiple choice questions on Electrical Machines 1.        To eliminate the single phasing torque in an ac servomotor, the rotor must have a)       Both high resistance and reactance. b)        High resistance. c)        High reactance. d)       Large air-gap 2.        If a single-winding single-phase motor is running in a particular direction a)       Both the rotating fields (rotating in opposite directions) have the same strength. b)       Forward rotating field is slightly stronger than the backward field. c)        Forward rotating field is much stronger than the backward field. d)       Backward field is stronger than the forward field. 3.        A single-winding single phase motor has a)       Low starting torque b)       Zero starting torque c)        High starting torque d)       Starting torque equal to full-load torque 4.        A single phase stator winding when excited with ac voltage produces a)       A single rotating field r

Important multiple choice questions in Power systems 1.        To limit current chopping in vacuum circuit breakers, the contact material used has a)       High vapour pressure and low conductivity properties b)       High vapour pressure and high conductivity properties c)        Low vapour pressure and high conductivity properties d)       Low vapour pressure and low conductivity properties 2.        For the same rupturing capacity, the actual current to be interrupted by an HRC fuse is a)       Much less than any circuit breaker b)       Much more than any circuit breaker c)        Equal to the circuit breaker d)       None of these 3.        For protection of parallel feeders fed from one end, the relays required are a)       Non-directional relays at the source end and directional relays at the load end b)       Non-directional relays at both the ends c)        Directional relays at the source end and non-directional at the load end d)       Directi