Resistance

• Equation for proportionality of V = I X R

  Potential difference = current x resistance

  Symbols: V = I x R

  Units: V = A x Ω
• Types of resistors

  A) thermistor

  B) diode

  C) resistor

  D) variable resistor

  E) LED

  F) LDR

  
• A light dependant resistor makes the resistance go up if the light intensity of the surroundings goes down, vice versa

  
• A thermistor makes the resistances go down as the temperature of the surroundings go up
• A variable resistor is one which can be adjusted to change the resistance of the circuit.

  
• A diode is a one-way valve that allows current to flow in one direction only.
• Diodes are made from a semiconductor material such as silicon
• Diodes are useful for devices such as radio receivers, to make sure the message only goes in one direction
• Unlike regular diodes, which are designed to prevent electricity from flowing in the wrong direction, LEDs are designed to convert electricity into light
• An LED, or Light Emitting Diode, is a special type of diode that emits light when current is passed through it
• LEDS come in many different colors, including red, green, blue, and even white