Electrical and Mechanical Engineering

Question 1

Electricity/Electrical

Answer 1

• uses conductors (metals & alloys, usually copper) to link different circuit components (motor, heater, light, power source, switch, fuse, etc).
  -most often uses AC power and high current (exception: small DC motors).
• EX: fan or heater, flashlight
• doesnt think

Question 2

Electronics

Answer 2

• (also uses conductors to links components)
• uses semiconductors (usually silicon or germanium) to perform complex tasks (control current flow, store information, etc)
• always uses DC power and low current.
• EX: Cell phone, calculator, computer, toy car, ps5, switch, smart watch, radio, printer
• thinks

Question 3

What is in common with electronics and electricity?

Answer 3

Both electric and electronic circuits use insulators (plastic, rubber, ceramic, glass) to prevent short circuits and protect the user and equipment.

Question 4

5 electrical conductors

Answer 4

silver, gold, copper, steel, sea water

Question 5

5 electrical insulators

Answer 5

glass, dry wood, oil, rubber, diamon d

Question 6

4 Electrical Functions!

Answer 6

Power Supply
Conduction / Insulation / Protection
Control
Transformation of Energy

Question 7

What is a function

Answer 7

Function is what something does, the job it accomplishes.

Question 8

Power Supply

Answer 8

Power Supply: provides the “push” (potential difference, or Voltage) that moves electrons in the circuit (see next slide)

Question 9

Conduction

Answer 9

Conduction: wires (usually copper) connect components of the circuit

Question 10

Control

Answer 10

(3) Control: performed by a component that can open or close a circuit branch. There are many types of switches (pushbutton, toggle, slider, momentary, etc)

Question 11

Transformation of Energy

Answer 11

Transformation of Energy: the main “job” of a circuit element.

Components in a circuit can transform electrical energy into many other forms, allowing them to perform a task.

• light bulb - heating element - electromagnet - piezoelectric crystal

Question 12

Insulation

Answer 12

Insulation: prevents electric current from flowing -rubber/plastic

Question 13

Protection

Answer 13

Protection: component that automatically cuts current flow when there is a power surge. Protects the circuit, not the human
- fuse - circuit breaker

Question 14

Fuse

Answer 14

(one time deal, it explodes and burns out instead of the actual thing)

Question 15

Component of linking

Answer 15

Component: a solid part or fluid that performs a mechanical function (Ex: a metal gear in a clock; the oil in a hydraulic piston)

Question 16

Linking

Answer 16

Linking: the mechanical function performed by any component that connects different parts of a technical object.

→ A linking component connects parts of an object.

Question 17

Direct

Answer 17

A link is direct when two parts hold together without a linking component

Question 18

Indirect

Answer 18

A link is indirect when the parts require a linking component to hold them together.

Question 19

Rigid

Answer 19

A link is rigid when the linking component or the surfaces of the linked parts are rigid.

Question 20

Flexible

Answer 20

A link is flexible when the linking component or the surfaces of the linked parts can be deformed. Springs and rubber are often used in flexible links

Question 21

Removable

Answer 21

A link is removable when the linked parts can be separated without damaging either their surface or the linking component (if present). Nuts and screws, for example are used in removable links.

Question 22

Non-removable

Answer 22

A link is non-removable when separating the linked parts damages their surface or the linking component.

Question 23

Complete

Answer 23

A link is complete when it prevents the linked parts from moving independently of one another.

Question 24

Partial

Answer 24

A link is partial when a least one part can move independently from other parts.

Question 25

Direct / indirect

Answer 25

Direct / indirect (Is there something extra needed to hold components together?)

Question 26

Rigid / flexible

Answer 26

(Can the link be deformed, and does it return to its original state?)

Question 27

Removable / non-removable

Answer 27

(Will the components or links be damaged if separated?) Nails are considered non-removable Screws are considered removable

Question 28

Complete / Partial

Answer 28

(can the parts move relative to each other?)

Question 29

Component of guiding

Answer 29

Component: a solid part or fluid that performs a mechanical function (Ex: a door hinge; the track of a sliding window)

Question 30

Guiding

Answer 30

Guiding: the mechanical function performed by any component that controls the motion of one or more moving parts.

Question 31

Types of Guiding

Answer 31

Translational, Helicoidal and Rotational

Question 32

Translational guiding

Answer 32

Translational guiding: moves back and forth along a straight line Examples: drawers, sliding window + SYMBOL

Question 33

Rotational guiding

Answer 33

Rotational guiding: ensures an object rotates Examples: scissors, bicycle wheel SYMBOL

Question 34

Helicoidal

Answer 34

Helicoidal guiding: rotating a component ensures a translational motion (helical) EXAMPLES: Clamp, screw press, faucet, jar cap SYMBOL

Question 35

Adhesion

Answer 35

Adhesion is the phenomenon by which two surfaces tend to remain in contact with each other without slipping

Question 36

Battery vs Outlet power source

Answer 36

Battery (DC, low power) -Outlet (AC, high power) -photovoltaic cell

Question 37

Friction

Answer 37

Friction is a force that resists the slipping of one moving part over another

Question 38

Lubrication

Answer 38

Lubrication is the mechanical function performed by any component that reduces friction between two parts.

Question 39

Types of lubricant

Answer 39

Liquid, semisolid, solid

Question 40

Liquid lubricant

Answer 40

Water, oil (vegetable, animal and mineral)

Question 41

Semisolid lubricant

Answer 41

Suet, Vaseline, animal fat, vegetable fat

Question 42

Solid lubricant

Answer 42

Graphite, paraffin

Question 43

Motion transmission

Answer 43

Motion Transmission is the mechanical function of relaying a motion from one part to another without changing the nature of the motion. (rotation → rotation)

Question 44

2 Types of Dynamic Electricity

Answer 44

AC/DC

Question 45

AC current

Answer 45

Electrons “wiggle” back and forth. This “wiggling” is caused by the AC power source. The motion is communicated from electron to neighboring electron all along the wire. Power generating stations produce AC current. AC current is optimal for sending electricity long distances (DC current has too much loss).

Question 46

DC current

Answer 46

Electrons travel through the conductors from one end to the other, pushed by the potential difference (voltage) of the DC power source (ex: battery).

Question 47

DC current ex

Answer 47

Most electronic devices function on DC current. The “box” on power adaptors converts the AC current from the wall outlet to DC current for the electronic device.

Question 48

AC current ex

Answer 48

AC current can power motors, heating elements, and other simple mechanical devices.

Question 49

Electric current

Answer 49

An electric current is the orderly flow of negative charges carried by electrons

Question 50

Conventional current

Answer 50

The conventional direction of a current is from the positive terminal of a power supply towards the negative terminal. (This is opposite of Electron Flow.) (Think back to our electric field drawings from static electricity: FROM positive TO negative!)