Resistor Symbols(Info)

What has a fixed resistance?

Fixed Resistor

What has resistances that can be changed?

Variable Resistors

What do Variable Resistors contain?

Rheostats and Potentiometers

What are Potentiometers useful for?

Changing the voltage drop across a component in a circuit

What are Rheostats useful for?

Changing the current in a circuit and can be used as light dimmers or to control the speed of small motorized devices

What do Fixed Resistors use?

A color band system to enable us to determine their resistance in ohms

What do Fixed Resistors use?

A color band system to enable us to determine their resistance in ohms

What does the first color give?

The first number

What does the second color give?

The second number

What does the third number give?

The multiplier or the number of 0s behind the numbers

How could you go about determining the value of resistance in the circuit?

By measuring directly by using an ohmmeter

How do you use an ohmmeter?

Remove the device with unknown resistance from the circuit or disconnect the power source from the circuit

How can the resistance be measured?

By attaching the ohmmeter leads across both ends of the device

What can you used if there’s no ohmmeter available?

Ammeter or Voltmeter

What is a Voltmeter connected in?

Parallel with the resistor

What is an Ammeter connected in?

Series with the resistor

Via Ohm’s Law, Resistance is equal to:

V and divided by I