Circuits Flashcards
What is resistance?
The amount of voltage needed to drive a current through a circuit.
Why would we need to increase the resistance in a circuit?
To limit the energy being transferred, for example this can result in a dimmer light that was too bright.
How do you reduce a circuit’s resistance?
Get a component that has a low voltage.
What is an ohmic conductor?
When the resistance of a circuit is constant and the current and voltage in a circuit is directly proportional.
What factor can change the constant of resistance?
Temperature
On a current, voltage graph, what does the gradient represent?
The resistance
On a current, voltage graph, what does the steepness of the gradient tell us about the resistor?
The flatter it is the more resistance the resistor has.
What does LDR stand for?
Light- dependant resistor.
What is a light dependant resistor and what does it do?
What is the correlation between light intensity and the resistance of an LDR?
The higher the light intensity the lower the resistance.
What is AC?
Alternating current, where the current is constantly goes in different directions in the circuit, and its voltage and current goes from positive to negative.
Why do we use AC in circuits?
Because its easier for a transformer to change the potential difference and current in a circuit than a DC.
In the UK main system, what is the type of current and what is its frequency and voltage?
AC, 50Hz, 230V
In an AC what does the frequency tell us?
The amount of times the current goes back and forth in a circuit per second
What is DC?
When the current goes in one direction.
