components in series and parallel circuits Flashcards
(22 cards)
in a series circuit, current isβ¦
the same throughout
what does a fuse do
when the current becomes larger than the value of the fuse, the fuse wire melts which stops the flow of the current in the circuit
resistanceβ¦. as light intensity increases
decreases
why would you might place a thermistor in water for an experiment
- to be able to control its temperature
- to prevent intense heating
state the equation linking power energy and time
P = E/t
what does a resistor look like
just a box - no line through it it is resisting being stabbed
how can you tell from a graph that the resistance of the filament lamp changes as the voltage increases
the gradient changes
explain the changes across a current voltage graph for a fillament lamp
lamp heats up, so there is greater chance of electron collisions hence the resistance inside the lamp increases
suggest why you should keep the temperature of a wire constant when investigating its resistance
resistance of a wire changes with temperature
what does a resistance voltage graph look like
a horizontal line drawn above the x axis
describe the relationship between the resistance of an LDR and the diameter of the hole
non linear and inversely proportional
state two benefits of using parallel circuits
- all lamps can be switched on and off and arent dependant on each other
- if one component breaks, not all have to be fixed
what is the current like in a series circuit
the same at every point
what does current do at junctions
splits/branches
what is voltage like in parallel circuits
same between the components
components with linear graphs
- fixed resistors
- wires (at constant temperature)
components with non linear graphs
- filament lamps
- diodes
- LDRs
- Thermistors
why does resistance increase as current increases in a filament lamp
- higher current increases temperature
- causes atoms to vibrate more
- more difficult for free electrons to flow through
what happens to resistance in a thermistor as temperature changes
resistance is high in cold temperature and low in hot temperature
what happens to resistance of LDR as light intensity changes
as light intensity increases, resistance decreases
how does current change when a resistor is added in parallel to another resistor
current increases as it creates more paths for the current to flow
If you add two identical leds and resistors, how will the ammeter reading change
- resistance decreases
- as thereβs an extra path in the circuit
- so resistance halves
- voltage across branches is the same
- current increases
- current in ammeter doubles
