Plumbing Science Flashcards
What is the unit for resistance?
Ohms
What is the power in a domestic property?
230V or 240V
What is the unit for power in an appliance?
Watts
What is the unit for electromotive force?
Voltage
What are the names of the two triangles?
The power triangle and The Ohm’s law triangle
What is the unit of electrical energy?
Joules
What is the unit for current?
Amperes
In a domestic property, an appliance has a fuse size of 3 amp. What is the maximum
power rating of the appliance?
720w or 0.72kW
An appliance has a 5 amp fuse and needs 1.2kW of power. What is the voltage required?
240v
What would be the resistance of a domestic appliance if the fuse size was 3 amp?
80 ohms
What is the fuse size for a domestic appliance which has 1,200 ohms resistance?
0.2 amp
What does DC stand for and where does it get it’s power from
Direct current - From batteries
What does AC stand for and where does it get it’s power from?
Alternating current - Mains
If an appliance had a fuse rated at 13 amp and the resistance was 32 ohms, what would the voltage be?
415v
What does Ohms law triangle show the relationship between?
Voltage, Current and Resistance
What does the power triangle show the relationship between?
Watts, Amps and Volts
An appliance needs 5 amp fuse and needs 1.2Kw of power. What is the voltage required?
240v
What is the system called containing an earth rod?
TT
What is the system called where the neutral wire and the earth wire are connected to the same block?
TNC
What is the system called where the earth cable is at a separate point?
TNS
What is the role of a miniature circuit breaker (MCB)?
It protects one appliance or circuit and trips out if an overload is detected
Where is the miniature circuit breaker found?
In the consumer unit
Where is a residual circuit breaker found?
In modern consumer unit
What voltage of tools should be used with plug in RCDs?
230v
What is the role of an RCD?
Trip out if there is an earth fault
Where is the residual circuit breaker with overload (RCBO) located?
Found in the consumer unit
What is the purpose of gears in a mechanical engineering system?
Increase or decrease torque
Which property measures a materials resistance to being deformed?
Hardness
In MES, why is it important to understand the concept of torque?
It measures the force causing rotation
Which type of conversion is typically found in an internal combustion engine?
Chemical to mechanical
What role do fluids play in a hydraulic system?
They transfer force through pressurised liquid
What is the primary difference between force and pressure?
Force is measured in Newtons whereas pressure is measured in pascals
What material is commonly used for modern residential water supply pipes due to its resistance to corrosion and ease of installation?
PVC (Polyvinyl chloride)
Why is stainless steel preferred over other metals for plumbing in areas prone to corrosion?
It is highly resistant to rust and corrosion
Why is brass often used for fittings in plumbing?
Because of it’s strength and it’s ability to resist high temperatures
In a hydraulic system, pressure is typically measured in which unit?
Pascals
In a mechanical engineering system, what does the term ‘velocity’ refer to?
Speed of an object in a specific direction
Which material is used for compression fittings in plumbing?
Brass
What is the term for the ability of water to flow between narrow spaces?
Capillarity
What is the main component in natural gas?
Methane
How many pascals are equivalent to 1 bar of pressure?
100,000 Pa
Which property measures the resistance of a material to deformation or bending?
Hardness
Which scientific principle is used in plumbing to prevent backflow in water systems?
Atmospheric pressure
Why are U-bends or P-traps used in plumbing systems?
To prevent sewer gases from entering the building
Which unit is used to measure the pressure of water in a plumbing system?
Pascals
In a gravity-fed system, which factor has the most direct impact on water pressure at an outlet?
Temperature of water
When using a siphon in plumbing, which scientific principle is primarily at work?
Gravity and atmospheric pressure
