# AS AQA Phys Unit 1 (6)

Practice exam questions/important points with relevent answers/descriptions on the reverse side. This set is for I/V characteristics and for resistivity and superconductivity.

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What is the characteristic Current/Voltage graph of a filament lamp and what does the shape of the gradient mean? (2 marks)
The characteristic I/V graph for a filament lamp is a curve (1) The curved shape means that the resistance is changing (1)
1 of 5
How are diodes designed? (1 mark)
To let current flow in one direction only (1)
2 of 5
State how the resistance of a filament lamp changes as the temperature increases. (1 mark)
Resistance increases as the temperature increases (1)
3 of 5
Name the units for resistivity and give the equation (2 marks)
The units for resistivity are the ohm-metres (1) Resistivity can be calculated by multiplying resistance by cross-sectional area and dividing both by length (1)
4 of 5
What happens to a component if it is cooled down to its transition temperature? (2 marks)
The component becomes a superconductor (1) and its resistivity, and therefore resistance, equals zero (1)
5 of 5

## Other cards in this set

### Card 2

#### Front

How are diodes designed? (1 mark)

#### Back

To let current flow in one direction only (1)

### Card 3

#### Front

State how the resistance of a filament lamp changes as the temperature increases. (1 mark)

#### Back ### Card 4

#### Front

Name the units for resistivity and give the equation (2 marks)

#### Back ### Card 5

#### Front

What happens to a component if it is cooled down to its transition temperature? (2 marks)

#### Back 