1) Maximum current required to start the motor. a) Ampacity  b) Locked-rotor current  c) Peak current  d) Direct current 2) Rotating part of electric motor which is typically constructed of a laminated steel core containing current-carrying copper wires. a) Rotor  b) Stator  c) Generator  d) NOTA 3) A type of DC motor in which the field windings is connected parallel with the armature. a) Shunt-wound motor  b) Series-wound motor  c) Compound-wound motor  d) Synchronous 4) An electrical switch which is operated mechanically by the movement of some other piece of material or machine. a) Limit switch  b) Pressure switch  c) Float switch  d) Time switch 5) Two-twenty (220) volt line is advantageous over the 120 volt line for the reason that ______________. a) economy is attained by using smaller wire  b) there is lower power loss  c) there is smaller percentage of power drop  d) All of the above 6) Electrical equipment such as alternators, generators and electric motors operate based on what law? a) Kirchhoff’s Law  b) Electromagnetism  c) Ohm’s Law  d) Newton’s Law 7) It is a variable resistor used to control current. a) Potentiometer  b) Rheostat  c) Wirewound type  d) Carbon film type 8) According to PEC, the maximum load to be served by the branch circuit conductors must not be more than ____ of the ampacity of the conductors. According to PEC, the maximum load to be served by the branch circuit conductors must not be more than ____ of the ampacity of the conductors. According to PEC, the maximum load to be served by the branch circuit conductors must not be more than ____ of the ampacity of the conductors.  a) 60%  b) 70%  c) 80%  d) 90% 9) A type of cable that is a fabricated assembly of insulated conductors enclosed in flexible metal sheath. It is use both on exposed and concealed work. a) Armored cable  b) Metal clad cabale  c) Mineral insulated cable  d) Non-metallic sheathed cable 10) It is an electrical element that acts as a switch but without physical contact and also amplifies the signal passing through it. a) Capacitor  b) Inductor  c) Transistor  d) Diode 11) Size of AWG No. 10 wire is: a) 2.0 mm2  b) 3.5 mm2  c) 5.5 mm2  d) 8.0 mm2 12) The maximum value of torque produced by the motor during overload without stalling. a) Locked-rotor torque  b) Pull-up torque  c) Breakdown torque  d) Full-load torque 13) It is a process of reversing the polarity of the rotating armature. a) Armature  b) Commutation  c) Rotor rotation  d) Magnetism 14) Recommended light level or illumination for feeding area for dairy barns. a) 110 lx  b) 110 fc  c) 220 lx  d) 220 fc 15) In a simple circuit, when measuring the current in the line by a multimeter, the probe should be connected in ________ with the line. a) series  b) parallel – for measuring voltage  c) series-parallel  d) wye-delta 16) One application of a megger is to measure the strength of insulation resistance in ______. a) Milli ohms  b) Mega ohms  c) Ohms  d) Kilo ohms 17) Component of solar PV system that regulates the voltage and current coming from the PV panels going to battery and prevents battery overcharging and prolongs the battery life. a) PV module  b) Inverter  c) Battery  d) Solar charge controller 18) The starting current of an electric motor is ______ compared to its running current. a) Higher  b) Lower  c) The same  d) None of the above 19) This happens when the electric field in a material is large enough, in which conducting paths suddenly appear in the material. Electrons flow along one or more conducting paths, creating electrical sparks. a) Electrical breakdown  b) Short circuit  c) Ground  d) Electric circuit 20) These are control devices consisting of coils of wire acting as electromagnets that pull a plunger (iron bar) into the core when energized. a) Solenoids  b) Signalling devices  c) Mechanical devices  d) Sensors 21) A swine house, having a dimension of 20-ft wide by 60-ft long, requires an illumination of 200 lux. If a 25-watts fluorescent lamp with lighting intensity of 100lumen is provided, how many bulbs will be needed for the structure? a) 293 bulbs  b) 323 bulbs  c) 423 bulbs  d) 223 bulbs 22) A circuit having two inductors, 75 microH and 125 microH is connected in series. Determine the total inductance of the circuit. a) 200 microH  b) 213.3 microH  c) 46.875 microH  d) None 23) A 2-m x 10-m space is supplied with a light of 400 lux. How many foot-candle does a lamp provide into the space, assuming a coefficient of utilization of 0.80 and a service factor of 0.7. a) 25.82 foot-candle  b) 12.82 foot-candle  c) 20.82 foot-candle  d) 10.82 foot-candle 24) A 12-ampere air-moving device with a power factor of 0.85 was connected to a 240-volt line. What is the power in the circuit? a) 2,200 watts  b) 2,448 watts  c) 2,848 watts  d) None of the above 25) Find the total impedance of a series circuit containing two 25-ohm resistors and an 75-ohm inductive reactance. a) 125 ohms  b) 90 ohms  c) 50 ohms  d) 100 ohms 26) What is the real power of a circuit if the apparent power is 1000VA and the reactive power is 800 VAR? a) 1280W  b) 200W  c) 600W  d) 900W 27) In a 110V, 60 hz source, determine the impedance of a combine resistor and an inductor in series if the resistor value is 500 ohms and the inductor value is 2 Henrys. a) 754.6 ohms  b) 500.5 ohms  c) 904.7 ohms  d) 1254 ohms 28) When a 2-ohm, 4-ohm and 6-ohm resistors are in wye connection, the equivalent resistors in delta connection are: a) 7.3, 22, 12 ohms  b) 7.3, 22, 11 ohms  c) 8.3, 22, 12 ohms  d) 8.3, 22, 11 ohms 29) In a 220V, 60 Hz source, determine the total impedance of a combine capacitor and inductor in series if the capacitive reactance is 90 ohms and the inductive reactance is 200 ohms. a) 290 ohms  b) 420 ohms  c) 110 ohms  d) 280 ohms 30) Determine the supply voltage of an RL circuit as shown in the figure below. a) 120 V  b) 131 V  c) 72.25 V  d) 110 V 31) A poultry house has 220-volt supply, twenty-five 20-watt LED AC florescent lamps, a single phase 6-hp pump motor and scheduled to purchase a 700-watt incubator. Average ambient temperature is 29 °C. What should be the circuit breaker amperage? a) 20 A  b) 30 A  c) 60 A  d) Cannot be determined 32) The percent voltage drop must not exceed 2% for a 230-volt feeder line at 20 ampere rating. If No. 14 AWG wire of 2.58 resistance in ohm/1000ft is to be used, compute for the allowable wire length for a 2-wire feeder line. a) 18 meters  b) 12 meters  c) 10 meters  d) 60 meters 33) A circuit has a voltage source of 220V AC. The total load consists of a 50-ohm resistance, 86.7 inductive reactance and 86.7 capacitive reactance connected in series. What is the total current? a) 5 A  b) 10 A  c) 20 A  d) 30 A 34) How much should be budgeted annually for the electrical consumption of a 30-kW coconut oil expeller drawing 98 amperes current and having an electrical consumption of 0.05 kWh/kg copra? It expels 500 kg of copra per hour and operates 16 h/day at 270 days/year. Electricity costs PHP 8/kWh. Use 15% cost safety factor. a) P 1,050,000  b) P 1,650,000  c) P 995,500  d) P 993,600 35) What is power dissipated when a ½ amp current flows through a 5-ohm resistor? a) 2 W  b) 1 W  c) 1.25 W  d) 1.5 W

Rural Electrification/Problem Set 1

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