Unit 303

Question 1

What does ductility of a material refer to?

Answer 1

Its ability to be stretched without breaking

Question 2

If 0.150 m3 of water were heated beyond its boiling point, what volume of steam would be produced?

Answer 2

150 m3

Question 3

What is the unit of heat?

Answer 3

Joule

Question 4

What does the term ‘potential difference’ refer to?

Answer 4

Voltage

Question 5

Using Ohm’s law, calculate the voltage in a circuit that has a resistance of 75 ohms and a current of 2.5 amps.

Answer 5

30 volts

Example calculation: Voltage (V) = Current (I) × Resistance (R) = 2.5 A × 75 Ω = 187.5 V.

Question 6

What size of earthing cable should be used to bond gas and water mains pipework?

Answer 6

6 mm2

Question 7

When different metals are present together in a system of pipework, which type of corrosion is likely to occur?

Answer 7

Electrolytic

Question 8

What is the sl unit for temperature?

Answer 8

Kelvin

Question 9

What is the sl unit for mass ?

Answer 9

KG

Question 10

What is the derived sl unit for velocity ?

Answer 10

M/S

Question 11

What is the relative density of natural gas ?

Answer 11

0.6

Question 12

What is the relative density of air ?

Answer 12

1

Question 13

At what temperature is water at its most dense ?

Answer 13

4 degrees Celsius

Question 14

Which of the following is an alloy ?
Copper
Steel
Lead
Tin

Answer 14

Steel

Question 15

Which ancient mathematician designed a simple screw type mechanism ?

Answer 15

Archimedes

Question 16

What temperature in kelvin is 60 degrees Celsius ?

Answer 16

333

Question 17

Brass is an alloy of which two metals ?

Answer 17

Copper and zinc

Question 18

Which Sl unit determines the flow rate of a hot water tap ?

Answer 18

L/s

Question 19

How much will water expand when heated from 4 degrees Celsius to boiling point ?

Answer 19

4%

Question 20

What pressure would there be at the outlet of a tap if it was located 10m below the base of a cold water storage cistern ?

Answer 20

1 Bar (100kPa

Question 21

What unit of gas will be displayed on a domestic metric gas meter ?

Answer 21

M3/h

Question 22

Neutral water has a pH of ?

Answer 22

7

Question 23

What is the chemical symbol for Iron

Answer 23

Fe

Question 24

Disadvantage of a Ferrous Material ?

Answer 24

Rust

Question 25

Name Two alloys in the plumbing industry.

Answer 25

Solder and Brass

Question 26

What is the symbol on a Brass Fitting and what’s its meaning ?

Answer 26

CR ( Corrosion Resistant)

Question 27

What plastic is used on waste discharge branches and can be solvent welded ?

Answer 27

Polyvinyl Chloride (PVC)

Question 28

What are the 3 types of stress applied to materials ?

Answer 28

Tension, Compression and Shear

Question 29

How much does water expand when turned into ice ?

Answer 29

10%

Question 30

What can be used within a solar hot water circuit to protect against freezing ?

Answer 30

Glycol

Question 31

What’s the equation for mechanical advantage ?

Answer 31

Mechanical advantage = load/effort