# Electrical Connections

## Basic Electricity

• #### Question 1

What, exactly, is necessary to establish electrical continuity between two wires? If I want to have an electric current flow out of one wire and into another, what must be done with those two wires to make that flow path complete?

Conversely, what things might prevent continuity from being established between two wires when they are supposed to electrically connect with one another?

• #### Question 2

What type of electrical test would be the most direct means of checking the integrity of an electrical connection between two conductors? Explain your answer.

• #### Question 3

What is the difference between a plug and a jack? What are these two devices used for? Draw the schematic diagram symbols for single-conductor plugs and jacks.

• #### Question 4

What is a terminal block, or terminal strip? How are these devices used to make electrical connections between different conductors?

• #### Question 5

What is generally considered to be the maximum number of individual wires that may be attached to a single terminal on a terminal block?

• #### Question 6

Wire nuts are special electrical connection devices commonly used in residential power wiring. Describe what a “wire nut” is and how they are used to make connections between wires.

• #### Question 7

How are connections made between the various wire ends of components inserted into printed circuit boards (“PCBs”)?

• #### Question 8

Suppose this circuit has a problem: the light bulb does not light up when the switch is turned “ON”. You suspect that a “bad” connection may exist in the circuit which is preventing current. How would you test the integrity of each connection using a voltmeter only?

• #### Question 9

Map the interconnections between holes in a typical solderless breadboard, also commonly known as a proto-board:

• #### Question 10

Show how to build a simple circuit consisting of a battery, a lamp, and a switch, mounting the lamp and switch on a solderless breadboard (also known as a proto-board):

• #### Question 11

What is soldering? What is solder?

• #### Question 12

An alternative to soldering components into printed circuit boards is to use a technique called wire wrap. Describe what “wire wrap” is and what applications it might be suitable for.

• #### Question 13

Solderless breadboards provide convenient means for electronics hobbyists, students, technicians, and engineers to build circuits in a non-permanent form. The following illustration shows a three-resistor series circuit built on a breadboard:

The interconnections between the metal spring clips within the holes of the breadboard allow continuity between adjacent leads of the resistors, without the resistor leads having to be jammed into the same hole.

However, new students often get themselves into trouble when first learning how to use solderless breadboards. One common mistake is shown here, where a student has attempted to create a simple single-resistor circuit:

What the student has actually created here is a short circuit. Re-draw this circuit in schematic form, and explain why this circuit is faulty.