Circuits

Question 1

In series circuits…

Answer 1

• the more cells, the higher the potential difference
• potential difference is shared between all components
• there is only one loop, if your remove a component the circuit is broken
• the same current flows through the entire circuit
• total resistance is the sum of the resistance of all resistors in the circuit

Question 2

In parallel circuits…

Answer 2

• each component is connected separately except ammeters which connect in series
• if you remove one component it will hardly affect the others
• potential difference is the same across all the components
• current is shared between each loop, sum of current in each loop = total current of circuit
• adding loops and components decreases total resistance

Question 3

What is ohms law

Answer 3

V = IR
Voltage = current x resistance
- if V and I are directly proportional, R stays constant

Question 4

What does ohms law state

Answer 4

The current through a conductor is directly proportional to the potential difference across it
- only relevant at constant temperatures

Question 5

What are ohmic conductors

Answer 5

Electric conductors that obey Ohm’s law
- fixed resistors
- wires
- heating elements
* make a straight line through origin when plotted on an IV graph

Question 6

What are non ohmic conductors

Answer 6

Don’t follow Ohm’s law
- filament lamps

Question 7

Why are filament lamps non ohmic

Answer 7

• their current and potential difference aren’t directly proportional, this is because the resistance of the lamp increases as it’s temperature increases