1. 18240 Element two - Components INPUTS OUTPUTS PURPOSE TYPICAL USE

2. Battery Switch Bulb LED Transistor Resistor LDR Variable resistor Thermistor Capacitor Diode Buzzer

3. Component - Battery Purpose Input output Typical use To provide a voltage which will drive a current when connected to a circuit. Chemical energy Electrical energy To provide portable energy source for an mp3 player

4. Component - LED Purpose Input output Typical use Visible indicator of circuit state Electrical energy Light energy Power Indicator on stereo

5. Component - Switch Purpose Input output Typical use To stop or allow current to flow in a circuit Physical movement Electrical continuity To turn your stereo power supply on and off

6. Component - Transistor Purpose Input output Typical use To amplify or control a current Small current Large current Amplifying a signal or switching a voltage

7. Component - Bulb Purpose Input output Typical use Converts electrical energy into light energy Electrical energy Light energy To light a room

8. Component - Resistor Purpose Input output Typical use To control currents and voltages in circuits current voltage To control the current in an LED

9. Component – Variable Resistor Purpose Input output Typical use To control current and voltage in a circuit Mechanical movement Change in resistance Volume control

10. Component – Light dependent resistor Purpose Input output Typical use To control current or voltage in a circuit depending on the amount of light Light energy Change in resistance Light sensor

11. Component - Thermistor Purpose Input output Typical use To control current or voltage in a circuit depending on temperature temperature Change in resistance Temperature sensor

12. Component - Buzzer Purpose Input output Typical use To convert electrical energy into sound DC current Buzzing sound To signal an alarm

13. Component - Diode Purpose Input output Typical use To allow current to flow in one direction only Voltage Current flowing in one direction only Converting AC to DC

14. Component – Capacitor Purpose Input output Typical use To store electrical charge. Electric charge Voltage Smoothing DC voltage levels