Resistance

Question 1

What is a ‘Light Dependent Resistor’?

Answer 1

• A special type of resistor that changes its resistance depending on how much light there is

Question 2

What is seen with a light dependent resistor?

Answer 2

• Bright light resistance falls

- Darkness resistance is highest

Question 3

What is seen with a thermistor?

Answer 3

• In hot conditions, the resistance drops

- Cool conditions, the resistance increases

Question 4

What does a thermistor depend on?

Answer 4

• The resistance depends on temperature

Question 5

Describe what happens when there is an electrical current in a resistor

Answer 5

• There is an energy transfer which heats the resistor

Question 6

Why is there an energy transfer when there is an electrical current in a resistor?

Answer 6

• Because of electrons colliding with ions with the lattice that makes up the resistor as they move through it

Question 7

What do the collisions do?

Answer 7

• They give the ions in the lattice extra energy which is then emitted as heat

Question 8

Describe what the heat effect does

Answer 8

• It increases the resistors resistance, which means less current will flow