Plumbing Science Flashcards
What is DC
Direct Current
What is the symbol for DC
2 lines one dotted
How to work out resistance
Voltage divide current
How to work out voltage
current x resistance
What is the equation for ohms law
Current x voltage x resistance
What is the equation for ohms law
Current x voltage x resistance
How to work out resistance
Voltage divide by current
How many base units are there on the SI system
7
What is length measured in
Mm cm m feet
What is mass measured in
G, Kg,
What is the unit of electrical current
Amps
What are the three letters in the power triangle
V,I,R
What are the 3 battery powered voltages
24, 18, 12v
How to work out current
Voltage divide by resistance
Which type of plastic becomes brittle in cold temperatures
Polyethylene
What is the process of water changing directly from ice to water vapor called
Sublimination
What happens to water when it freezes
Its density decreases
Which plastic is used for underground cold water mains?
MDPE
Which property measures the resistance of a material to deformation or bending?
Hardness
What is the Sl base unit for
length?
Metre
What is a solution to prevent pipes freezing in cold temps?
Wrapping pipes with insulation
What factor has the most direct impact on water pressure
Temp of water
What happens to water flow when pipe diameter decreases
flow rate decreases
What scientific principle is used in plumbing to prevent backflow
Atmospheric pressure
What appliance is an example of siphonic action?
WC cistern flushing mechanism
Halon Carbon gas what is it
used for?
It was originally used for fire fighting and has been used in refrigeration devices.
Its now not widely available due to its damaging effects on the ozone layer
What does the flow restrictor do
Flow restrictor will increase velocity after the restrictor
Which gas will rise to the top of the room?
Natural gas
What is the Ampage of
10kw electric shower
10000 divided by 230= 43.47
amps
Mechanical advantage is
load / effort
What scale is used to
measure temperature?
Celsius, kelvin, Fahrenheit
Whats the issue connecting copper tube onto galvanised steel
Electrolytic
Action
What is the most common copper tube used in plumbing
Table x or R250
Which metal is the most malleable
Lead
How do you work out density
Mass x volume
What heat sources are dispensed by a radiator
Convection and radiation
Which material gives High resistance to water flow
LCS
What offers the most resistance to water flow
Tight elbow
What offers the least resistance to water flow
A bend
What offers the least resistance to water flow
A bend
What happens when you reduce diameter
Increase in velocity
How much heat is required to raise 2kg of water 10 degrees
2 x 10 x 4.2 =84
If water is heated from-10 degrees to 10 degrees what is the change of state?
From a solid to a liquid
At what temperature is water at its most dense?
4 degrees
What is the boiling point of water at sea level
100 degrees
What is intensity of pressure measured in?
Pascal’s or N/m 2
What is the si unity of power
Watts
0.5 bar is how many pascals?
50000 pascals/ 50kpa
(1bar = 100000pascals)
What colour is the safety wire
Green and yellow
