1. Write down the specification of your tablet, laptop or mobile phone

2. Prefixes

3. Prefixes are easy ways to write large or small numbers. 0.034Volts is the same as 34milli Volts

4. Background information What does 2x2 equal? 8 What does 2x2x2 equal? 4 So 2 2 = 4 And 2 3 = 8 These are called powers

5. What does 2 x 100 equal? What does 2 x 1000 equal? 200 2000 Can you express these in the form of a power? 2 x 10 2 2 x 10 3

6. Explanation 10 2 = 10 x 10 10 3 = 10 x 10 x10 So going back to our previous examples 2 x 100 = 2 x 10 x 10 which equals 2x10 2 2 x 1000 = 2 x 10 x 10 x 10 = 2x10 3

7. These prefixes are on your data sheet 300mV for example equals 0.3V X10 -3 simply means move the decimal point three places back because the volt is a bigger unit than the milli volt

8. A very useful rule! ET2 requires you to use Ohm’s law a lot! They often use resistors in the k  range As long as you are using volts then the current will be in mA The current through a resistor of 3.5k  with a voltage across of 7V is I = V / R I = 7V / 3.5k  I = 2mA The kilo and milli cancel

9. VIR 10mA 1k  20mA 500  12V 10k  15V10mA RC  T 1/2 10k  10  F 1k  1F1F 100k  100nF Have a go at these examples Back to your Laptop etc