PART 3 Flashcards
States that the voltage or potential difference between two points is directly proportional to
the current or electricity passing through the resistance and directly proportional to the
resistance of the circuit.
Ohm’s law
Based on the 2009 Philippine Electrical Code, what is the minimum conductor size in mm2
for
a voltage rating of 0-2,000 volts when using copper wire?
2
A farmhouse requires a minimum conductor size of 2 mm2
which is equivalent to AWG ____.
14
(AWG 14 has 2.08 mm2
conductor size, AWG 16 should not be used in houses.
Except for the drop wire, the common household wires are AWG nos. 10, 12 & 14.)
Which electrical wire in the list below has the biggest cross-sectional area?
AWG 8
Which type of electrical wire has a maximum operating temperature of 90 oC?
THHN
ased on the Phil. Electrical Code, what is the minimum conductor size in mm2
for a voltage
rating of 2,001-8,000 volts when using copper, aluminum or copper-clad aluminum wire?
8
If V is voltage, I is current and P is power, according to Ohm’s law, V is equal to _____.
IR
Ohm’s law is applicable to _____.
Both DC and AC
Ohm’s law applies to both AC and DC circuits as long as mutual _________ of the circuit is
considered.
Inductance
The resistivity of annealed copper in ohm meters at 20oC.
1.72 x 10^-8
The resistance of a certain length of wire can be obtained by multiplying its ________ with
its length and dividing the resulting product by the cross-sectional area of the wire.
Resistivity
A farmstead has its farthest load located 350 linear meters from a single phase power source.
What length of the wire in meters should be used in the voltage loss computation?
700
In connecting electricity from a post to a farmhouse, a ______ wire is needed.
DROP
The minimum wire size for a farmhouse drop wire.
AWG 6
A solar powered slaughterhouse uses electrical stunning gun to make the animals insensible
to pain before the slaughter. What should be the voltage of the stunning gun?
220 Vac
Based on PAES 419:2000, the recommended lighting intensity in lux (lumen/m2
) for fruit
and vegetable processing plant are: 100 for outside the building, 200 for general indoor
locations, and ___ for working tables
500
A poultry layer area requires a brightness of 1,600 lumens. What is the wattage of a daylightcolor LED bulb that shall be used?
100
What is the voltage needed to light a 1-ampere LED bulb having a resistance of 220 ohms?
1 volt
V = IxR
= (1 A) x (220 ohms)
= 220 volts
How many amperes will pass through a circuit having ten 22-watt LED bulbs if the source is
220 volts?
1 watt
I = P/V
= (10 x 22 w) / (220 v)
= 1 Amp
What is the electrical energy consumption of a 15-kw vermin cast production shredder
plugged in a 220-volt source if it requires 2 hours to shred 1.5 tonnes of farm waste?
0.02 kwh/kg
Ec = PcTo / Wi
= 15 kw (2 h) / 1,500 kg
= 0.02 kwh/kg
Solid annealed copper has a resistivity of 1.72 x 10-8 ohm-meter at 20 oC. What is the
resistance in ohm-meter per linear meter of AWG 10 solid annealed copper wire having a
diameter of 2.588 mm?
3.27x10-3 ohms
A 240-volt industrial incubator uses a pair of 25-meter 7-strand AWG 10 copper wire having
a resistance of 3.87x10-3 ohm per linear meter at 65 oC. The heating load of the incubator is
composed of twelve 100-watt heating coils. What is the expected current in the main wire?
0.03 A
In off-grid farmhouse electrification, which one has the lowest operation and maintenance
cost?
Solar Home System
Which one has the highest operation and maintenance cost?
DIESEL GENERATOR