Farm Electrification Flashcards
CLSU - 2022 REVIEW
The Philippine electrical code specifies that all wall switches be installed on the _______________ of the door
latch side
This information provides the equipment manufacturer with a means of conveying to
costumers the rated electrical values and output capacities of equipment.
nameplate
A machine that converts electrical energy into mechanical energy is;
motor
It is the source of electrical pressure
Battery
Thermocouple
Generator
Percentage energy conversion of an average farm electric motor
75 %
It is the rate of converting energy
Answer: Power
The safe current carrying capacity of electric conductors.
ampacity
In the operation of AC generator, this variable is dependent on the speed of rotation of the motor and the number of poles.
Frequency
An item commonly referred to as convenient outlet
Receptacle
It is the portion of electric conductor that extends from service entrance switch to a certain group of outlets or to a single outlet.
Branch circuit
It is the number of wattage required by an electrical equipment in use in the building.
Electrical load
The minimum load design value for feeder
line and service entrance switch for general purpose barn
3 watts/ft
2 + 1320 hp each motor
A device use to protect branch circuit form overloading.
Circuit breaker or fuse
A circular mill refers to
The arc of a circle which has a diameter of 1/1000 of an inch
Factors to consider in selecting feeder lines.
- Size of wire to safely carry the current
- Type and location of wire adapted to its surrounding
- Size of wire to prevent excessive pressure loss or voltage drop
The wire that is extending from the distribution center to the consumer property.
Feeder line
It is the
centroidal point of the electric system
Electric load center
An electrical switch that controls the movement of some other pieces of materials or machines such as the travel of rope, chain, or carriage
Limit switch
Electrical equipment used to open and to close a circuit
switch
It is the amount of electrical pressure used not to advantage
Answer: Voltage drop
The unit used when specifying the intensity of light needed for various seeing task.
Foot candles
An allowable overload for a motor indicated by a multiplier that when applied to a normal horsepower rating indicates the permissible loading
Service factor
An electrically
operated device that converts one type of energy into another type
Transducer
A type of switch having contacts which are operated by magnetism
relay
It is the ratio of the quantity in working place to the quantity of light output from the source.
Room index
A magnetic device used to convert electrical energy into linear motion
Solenoid
A special kind of switch used to control temperature.
Thermostat
When the current is the same throughout all the parts of the circuit, the circuit line is
In series
It is an automatic switch used to control the level of liquid
Float switch
Most common electric motor speed
1700-1750 rpm
An electrical device that changes one value of AC
voltage into another value.
Transformer
A motor that develops more starting torque and is best suited for hardest to start load.
Repulsion start induction motor
A temperature
response mechanism used to control heating system and cooling system with the object of monitoring certain temperature without further personal attention.
Thermostat
A motor adapted for load that are easy to start such as centrifugal pumps, bench grinder, and others.
Split phase motor
Wiring connection used for lights on small appliance in farm buildings
Parallel connection
A rotating machine that converts electrical power into mechanical power.
Electric motor
The ratio of the maximum demand power to the total connecting load.
Demand factor
The ratio of the average load to the maximum demand of a system.
Load factor
A current which, when flowing through a given resistance, is practically unvarying and going in one direction only.
DC
The ratio of the true power to the apparent power.
Power factor
The property of an electrical circuit which opposes a change in current. It is also referred to as the fly wheel effect of an electric circuit.
Inductance
A rotating machine that converts mechanical power to electrical power.
Generator
Type of kilowatt
hour meter that is read exactly in like manner as the mileage indicator of the automobile.
Cyclometer type
The practical unit of inductance
Henry
A DC motor is used to
Convert electrical power to mechanical power
A kilowatt
hour meter with four dials and each dial is calibrated in opposite direction and dial readings from left to right give thousands, hundreds, tens, and single units of kilowatt hour respectively.
Pointer dial type
The property of the material that prevents the flow of current and at the same time electrical energy is converted into heat.
Resistance
The ratio of the applied voltage to the resultant steady state current
Impedance
The property of an electric circuit that enables it to store an electric charge.
Capacitance
Classification of AC motors according to power source with three sets of windings and 3 slip ring which produces three waves of voltage.
Poly phase
Type of distribution center where the kilowatt hour meter and the disconnect switch are located outside of one of the buildings
Outdoors
The practical unit of capacitance
Farad
The number of watts required for an electrical equipment in used in building.
Electric load
It refers to a certain amount of electrical pressure or volts used but not to advantage.
Voltage drop
Type of distribution center where the meter and the disconnect switch are located on a main distribution pole.
Pole type
Classification of AC motors according to principles and characteristics of operation that runs at an exact speed for all loads up to the pull out point.
Synchronous
Classification of AC motors according to principles and characteristics of operation that runs at constant speed, variable torque, variable Hp , average power factor and average efficiency.
Induction
Classification of AC motors according to principles and characteristics of operation that provides good starting torque, good running torque, variable speed and approximately constant Hp output.
Series
Which of the following are the motor’s jobs
All of the above
Classification of AC motors according to power source with a single set of windings and 1 slip ring which produces single wave of voltage.
Single phase
The most basic of all electrical controls and its purpose is to open and to close an electric circuit or to start and to stop the flow of electricity.
switch
It protects the motor due to its built
in overload device that automatically trips the switch in case too much current will flow to the motor.
Magnetic starting switch
A type of switch having contacts that is operated by magnetism.
Relays
It reduces the voltage to the motor when the motor is starting and applies the full voltage when the motor has gained sufficient speed.
Reduce voltage switch
This type of control is operated by electricity but it is used to control the flow of water, oil or gas.
Solenoid valve
This thermostat makes use of two unlike metals that do not expand in
the same amount.
Bimetallic thermostat
A type of switch has an electric clock that automatically operates switch contacts at definite time intervals.
Time switch
A type of thermostat is composed of two hollow metal discs, the switch and its contacts, and a frame for holding the parts in place.
Wafer thermostat
Type of switch that is useful in farm applications and is desired to limit the travel of rope, chain or carriage.
Limit switch
An automatic control having switch contacts which are operated according to various gas or liquid pressure.
Pressure switch
An invisible agent that produces such effects such light, heat, power, and sound.
Electricity
A mercury lamp with 50
ohms hot resistance is connected to a socket with 240 volt current supply . How much current is flowing through the lamp?
I = V/R
= 240 volt/ 50 ohms
= 4.8 amperes
A piece of wire has a resistance of 50 Ω. How much power is dissipated in the wire if it carries a current of 0.50A?
P = I^2 R
= (0.50A) 2 (50 Ω)
= 12.5 W
A 12 ampere electric blower with 0.85 power factor is connected to a 240 volt convenient outlet . Calculate the power in the circuit
P = E I cos 𝛉
= 240 volt x 12 amp x 0.85
= 2,448 watts
Two tractor headlights are connected
in series to a 12 volt battery, each having a resistance of 1 ohm. What is the current flowing in the circuit?
R = R1 + R2
I = V / R
= 12 volts / 2 ohms
= 6 amperes
