REE Board Exam- APRIL 2013 EE 1.A 115V DC shunt motor has an armature resistance of 200m ohm. If the full load armature current is 75A. Find the resistance needed to limit the armature starting current to 150% of the full load value. Allow brush contact drop of 2 volts. 2.Transformer rating expressed in_________. Ans. KVA 3.A 440V shunt generator has an armature and field resistance of 0.4 ohm and 200 ohms respectively. If the load resistance is 10 ohms, What is the terminal voltage of the generator? 4.A wind generator with an efficiency of 80% has a blade diameter of 20m. I f the wind velocity is 30 km/hr.How much power in kw is obtained from the generator? 5.A load of 10,000 KVA, 80% lagging is connected to a 13,200-volt line. How much capacitive reactance power is needed to correct the p.f to 97% lagging? 6.An uncharged 100uf capacitor is charge to a constant current of 1mA.Determine the voltage across the capacitor after 4 seconds? 7.Used to protect motors from overheating resulting from an overload is called________. Ans. Thermal Overload Relay 8.Two capacitor 6uf & 8uf connected in parallel. Find the voltage drop across the 8uf capacitor when the total voltage is 120v. 9.Fuse is used to protect motor from_______. Ans. Overcurrent 10. An unshaded lamp is placed at distance r1 above the ground & produces an illumination E1 at a point on the ground directly below the lamp. At what angle must the lamp be aimed on the ground to produce an illumination one-half of E1. 11.A test used to determine the equivalent resistance of induction motor is________. Ans. Blocked rotor test 12.The luminous intensity of a lamp is expressed in______. Ans. Candela 13.Formula at which the speed of magnetic field rotates. 14.Three 60mH inductors are connected in parallel. Find the total inductance. 15.Which of the ff. is used in p.f correction_______. Ans. Synchronous motor 16.Two resistors 8ohms & 12ohms are connected in parallel and then connected in series with 15ohms resistor.When the voltage drop across 8ohm resistor is 48V. What is the total source voltage? 17.In laboratory experiment the impedance of a coil was obtained at 50Hz & 30 Hz.These are 75.48 ohms & 57.44ohms respectively. What is the resistance and inductance of the coil.? 18. In two watt meter method the readings of the two wattmeters were 6717 & -2658 watts. Find the p.f? 19.A pump driven by 440volts 3phase Induction Motor lifts 1100 cu. Ft/min of water against a total head of 100ft of water. The efficiency of the pump and that of its motor are 0.75 & 0.92. The p.f of the motor is 0.90. What is the input power of the pump in HP? 20.A pump driven by 440volts 3phase Induction Motor lifts 1100 cu. Ft/min of water against a total head of 100ft of water. The efficiency of the pump and that of its motor are 0.75 & 0.92. The p.f of the motor is 0.90. What is the line current of the motor? 21.Two batteries are connected in parallel 10v, r=0.3 & 15v r=0.4 supplied to a load of 36ohms.Find the power to the load? 22.When the rotor of induction motor is opened the motor will______. Ans. Stop. REVIEW TRANSMISSION LINE, INDUCTION MOTOR , SINGLE PHASE POLYPHASE , ALTERNATOR , BASIC DC CIRCUITS,RESISTOR,CAPACITOR,&INDUCTOR, MAGNETIC CIRCUIT DC MOTOR DC GENERATOR POWER FACTOR CORRECTION TRANSFORMER BUS ADMITTANCE