Physics Resistor

electronics

•The branch of physics that deals with the

behavior of electrons using electronic

circuits are called

Electric circuit and electrical symbols

are important to understand to design any

electrical or electronic instrument.

electronics

•The branch of physics that deals with the

behavior of electrons using electronic

circuits are called

Electric circuit and electrical symbols

are important to understand to design any

electrical or electronic instrument.

active devices

•The components used in the electronic

circuits are

Electric Circuit

is the conductive path

for flow of current or electricity.

conductive wire

is used to establish

relation among source of voltage and

load.

circuit

flow of electricity from one point to

another point through a closed path is

called a

Power source

source for a basic circuit may be used to give the

current supply.

Battery, photocell, thermocouple

examples of power source

Connecting wire

are made up of

conductors that are used for the

transmission of current through the

circuit.

Fuse

protects electrical circuits

by stopping the flow of current when

the intensity of current exceed a

set value. It does this by melting a

special wire.

Bulb

When current

passes through the filament it emits

light.

tungsten

•In a light bulb, there is a filament

made up of

light energy

The electrical energy given

to the light bulb is converted into

Switch

an electric device

that is used to open or close the

circuit.

SPST, SPDT, DPST, Push-Button, Rotary

Types of switches

ground

•The common point in electric circuit is called

Open, Close, Short, Series, Parallel

five different types of electric

circuits:

earth,

chassis, equipotentiality

•Electric ground is categorized as

Earth ground

Also called reference or common ground

It can be used for a zero potential reference

point from where current is measured.

Earth ground

It is also for electrical shock protection.

Chassis ground

used to connect a piece of

electronic/electrical equipment to its main

frame.

Chassis ground

It is used when it is not possible to connect a

grounding conductor into the earth

Equipotentiality ground

It is used as an extra ground symbol, such as to

differentiate AC ground to DC ground within

single circuit

Also called signal ground

Active components

control the charge flow

in electronic circuits.

active elements

generate energy for any

device.

Diodes, Transistors,

voltage operated devices, Vacuum tubes,

voltage and current sources

examples of active elements

active elements

the core component to operate

any device.

current and voltage

•The two parameters to consider for proper

device operation are

Diode

two-terminal

semiconductor device that allows the flow

of current in one direction.

Diode

It's always polarized with an anode (A,

positive) and cathode side (C, negative).

Zener diode

the flow of current reverses

when it reaches a certain point called

Zener voltage.

Zener voltage

certain point where current flow reverses

Photodiode

converts light into electrical

energy.

Diode LED

is a standard

diode symbol with two small

arrows showing the emission

of light.

Passive elements

They don’t require

any external voltage to perform

their job.

Resistor, Capacitor,

Inductor

Examples of passive components

Resistor

reduces current

flow.

resistor

color code

Manufacturers typically

use a color band system

known as the

power rating

not

indicated in the resistor

color code.

4

For resistors with ± 5% or ± 10%

tolerance, the color code

consists of _ color bands.

5

For resistors with ± 1% or ± 2%

tolerance, the color code

consists of _ color bands.

Resistance

is opposition to flow of

current

size and type of wire

factors that affect resistance

fixed or variable

Resistors are either (types of resistors)

molded carbon composition, wire-wound, film

Three major categories of resistors:

Variable resistors

allow resistance to

vary

alphanumeric

system

Resistor values may be identified by

colored bands or by an

series, parallel, series-parallel

Three types of resistive circuits:

Ohm’s Law

states that the current I flowing in

a circuit is directly proportional

to the applied voltage V and

inversely proportional to the

resistance R, provided the

temperature remains constant.

Power

is given

by the product of potential difference V

and current I

Series Circuit

the

resistances are

connected end to end.

Parallel Circuit

the resistances are connected

across each other

series-parallel circuit

Combination of a

series and a

parallel circuit

To calculate total

resistance, use the

series and parallel

formulas

0.4 mA

Slight sensation

1.1 mA

Perception threshold

1.8 mA

Shock, no pain

9.0 mA

Pain shock, no loss of muscular

16 mA

Painful shock, let go threshold

23 mA

Severe painful shock

75 mA

Ventricular fibrillation, threshold

235 mA

Ventricular fibrillation, fatal

4000 mA

Heart paralysis

5000 mA

Tissue burn