Engineering - Exam Mistakes

Question 0

What is a screw tap?

Answer 0

A tool used to cut an internal thread into a hole

Question 1

What is a vernier?

Answer 1

A tool that can measure distances to high accuracy and sometimes have an electronic display

Question 2

What are the 3 hazards of using a centre lathe and how are these controlled?

Answer 2

Chuck key flying from chuck (take the chuck key out of the chuck before you turn on the machine)

Loose clothing / hair (tie back long hair, remove dangerous clothing)

Debris flying out away from the work piece (wear safety goggles to protect eyes and put lathe safety guard in place before activating machine)

Question 3

How do you draw straight line and diameter dimensions?

Answer 3

For straight dimension, lines coming down from the edges of the dimension, solid arrow heads and actual number between arrow and part

For diameter, diagonal line and solid arrow pointing to circle, the line becomes horizontal and the measurement is written at the end with a circle with a line through it in front of it (diameter symbol)

Question 4

Describe how you make a pattern

Answer 4

You need the coping and tenon saws, marking and measuring equipment and glass paper

You mark out the correct shape out of a prototype material, cut it to size and finish it to leave smooth edges

Question 5

What equipment do you need to cast?

Answer 5

Cope / drag, split pattern, runner / riser, sprue and crucible

Question 6

How do you machine a casted part to the correct size and tolerances?

Answer 6

You need the vertical milling machine, cutting tool and vice

You place the part into the vice ensuring the correct level and remove excess material

Question 7

What equipment do you need to make holes in a part?

Answer 7

You need to centre punch, pillar drill, the correct sized drill bit and the vice

Question 8

What are the 3 reasons that steel is hardened?

Answer 8

Increases wear resistance

Greater durability

Increases usefulness for more more applications that need harder materials

Question 9

What are the 3 disadvantages of hardening steel?

Answer 9

Material becomes more brittle

Labour intensive

Harder to shape or form

Question 10

Describe the process of case hardening low carbon steel

Answer 10

Material is heated using a gas torch

Material becomes red in colour

Material is introduced to carbon rich environment

Material is reheated

Above steps are done until material is as hard as it needs to be

Material is rapidly cooled

Question 11

How do you answer a 6 mark question in engineering?

Answer 11

3 points explained

Good English

Question 12

What 5 things does a designer always need to know about a product that they are going to make?

Answer 12

Does it need to be particularly light or strong

Dimensions

Target user

Price range

Scenarios that it will be used in

Question 13

Describe de-burring

Answer 13

Uses a grinder

Area to be made smooth is pressed against the grinder

Angle grinders can be used for getting rid of sharp or rough edges

Question 14

Describe de-scaling

Answer 14

A file, emery cloth and polishing wheel is used to take off the layer of oxide formed by hearing and to give the surface a shiny finish

Question 15

Describe tempering

Answer 15

Uses a controllable heat source to heat the object to a specific temperature for a while before quenching it

This allows some excess hardness to be removed so the material becomes more tough and less brittle

Question 16

What are the 3 main techniques of applying artwork to a surface?

Answer 16

Stencils and spray paint

Laser engraving

Air brush spray painting

Question 17

In what 4 ways has modern technology helped the development of electronic equipment?

Answer 17

Size of electronic equipment reduced because of microchips containing info and tiny circuit components

Use of ICT to test electronic circuits (don’t need to make prototype circuits)

Use of CAD to design circuits reduces the amount of prototypes that need to be made saving time and money

Cost reduction because more companies make circuit things and we have cheaper ways of making them

Question 18

Describe how you would finish a metal surface

Answer 18

Take off the top layer of a surface using the vertical milling machine

You need a milling machine, vice, cutting tool

Hold part in the vice with the surface to be finished held completely horizontal in all directions

Lower the cutting tool so that it is just below the surface and then slowly move it across the surface until the whole surface is finished

Question 19

How do write specification points for 2 marks?

Answer 19

Actually state what is needed

E.g. for the number of bikes to be held by the bike rack the specification point would be:

“The bike rack needs to be adjustable so that it can hold between 1 and 3 bikes at a time”

Question 20

Describe how you do a sectional view

Answer 20

The line (A - A) represents where you cut the object in half

Draw lines across / down to make sure the sectional view is to scale

Imagine you have the cut the object in half and are looking at the cut face of one of the halves. The parts that the “knife” has touched when cutting it are drawn on the sectional view as cross-hatched and for the parts the knife has not touched, only the outline is drawn

A ruler is used to make sure all measurements are correct

YOU HAVE TO WRITE SECTION A-A UNDERNEATH YOUR SECTIONAL VIEW

Question 21

What are the 4 advantages of CAD?

Answer 21

More accurate

Less human error

Save files to edit

Sent electronically

Question 22

What are the 3 disadvantages of CAD?

Answer 22

High initial costs

Needs training

Needs a computer

Question 23

What are the 4 advantages of CNC?

Answer 23

Used 24 hours a day

Accurate

Same component can be created over and over

Faster than making be hand

Question 24

What are the 3 disadvantages of CNC?

Answer 24

Initial costs high

Less workers so job losses

Not learnt within schools as much

Question 25

What are the 4 main smart materials?

Answer 25

Thermochromic ink that changes colour when exposed to hear

Heat shrinking materials that contract around wires when they are heated

Polymorph is a hard material that can be re shaped when placed in hot water

Smart wire that goes back to original shape when heated

Question 26

In what type of production is injection moulding used in and why?

Answer 26

Mass production

High set up costs

Question 27

How do motors work?

Answer 27

Current travels through copper wire

Positive and negative magnets pointing at wire cause a magnetic field

The current and magnetic field cause the wire to spin half a turn

Now the commutator reverses the current in the wire so that the wire can complete its rotation

The output is a rotary motion used to power a wheel or gears

Question 28

What are gears used for?

Answer 28

Increasing speed and decreasing torque or vice versa

Or changing direction of spin

Question 29

What is torque?

Answer 29

A measure of how much force acting on an object causes that object to rotate around an axis

Question 30

3 benefits of using plastic gears

Answer 30

Always corrosion resistant

Cheaper and easier to manufacture

Lighter than metals