1. PRACTICAL ELECTRONICS
MASTERCLASS
(Mr Bell)
(COMPUTERS REQUIRED FOR 1ST PERIOD)

2. Resistors One of the most important components in electronics.
Its purpose is to prevent a flow
of current and create a voltage reduction.
The resistor absorbs electrical energy, which it gives off as heat.
Resistance is measured in Ohms (ῼ - Greek omega symbol).
In your circuit it is used to protect the LEDs from over excessive current, which would destroy the LED.

3. Resistor Values
47kῼ or (47000ῼ) ± 5%

4. Resistor Colour Code
Now glue your Resistor Colour Code into your log book.

5. Resistor task:-
Using the resistor card work out the following resistor values. 1 2 3
?ῼ ± ?%

6. 1
10ῼ ± 5%
X1 ± 5%
=10ῼ ± 5%

7. 2
510ῼ ± 10%
What’s wrong with this resistor?
X10 ± 10%
= 510ῼ ± 10%

8. 3
1kῼ ± 5%
(k = 1000)
X100 ± 5%
= 1kῼ (1000ῼ) ± 5%

9. Prefix system of numbers