P6 - Resistors Flashcards
What is resistance?
When electrons hit atoms in a wire.
–[::::/::::]— what is this the symbol for?
A thermistor.
What causes resistance?
Collisions with spare nuclei in a conductor
What is another name for a variable resistor?
A rheostat
How do you increase Resistance?
Get a longer, thinner wire with a high temperature.
What is a variable resistor?
Something which changes the length of a wire.
How can you use a variable resistor?
As a dimmer switch.
What is resistance measured in?
Ohms.
What is the equation for resistance?
Resistance = Voltage / Current
Why are variable resistors useful?
They enable you to be able to alter the current in a circuit.
What is a variable resistor?
A variable resistor rheostat is a resistor whose resistance can be changed.
What can variable resistors be used for?
Altering the current flow through a circuit.
What happens when resistance goes up and down?
When the resistance goes up, the current drops. When the resistance goes down, the current rises
What does resistance cause in a circuit?
A reduce in current.
True of False: If you turn the resistance up, the current drops?
True - When the resistance increases, the current decreases.
