P1 - Electricity Flashcards
What is current ?
The flow of electric charge, units: ampere - A.
What is potential difference ?
The driving force that pushes charge around a circuit, units: volts - V.
What is resistance ?
Anything in the circuit which slows the flow of current down, units: ohms - Ω.
How does the current change in a circuit ?
In a single closed loop the current has the same value everywhere in the circuit.
How does resistance affect the current ?
The greater the resistance across a component, the smaller the current that flows through it (for a given potential difference across it).
How can you work out the charge of a circuit ?
Charge (C, coulombs) = current (A, amperes) × time (s, seconds)
Q = I × t
How can you calculate potential difference ?
Potential difference (V) = current (A) × resistance (Ω)
What is ohmic conductor ?
Components of a circuit that have resistance.
What can affect the resistance of a circuit ?
As temperature increases so does the resistance, whether components are in series or parallel, and the length of the conductor.
How is resistance changed in diodes ?
It depends on the direction of current, they happily let current flow one way but have a very high resistance if reversed.
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