P2 electricity- current, pb & resistance Flashcards
What is electric current?
The flow of electric charge.
What unit is current measured in?
Amperes (A).
What is the equation for charge flow?
Q = I × t (Charge = Current × Time).
What is potential difference (voltage)?
The push that makes electric charge move in a circuit.
What unit is voltage measured in?
Volts (V).
What is resistance?
The opposition to the flow of current.
What unit is resistance measured in?
Ohms (Ω).
What is Ohm’s Law?
V = I × R (Voltage = Current × Resistance).
What happens to resistance when the length of a wire increases?
Resistance increases.
How does temperature affect resistance in a wire?
Higher temperature increases resistance.
What type of component follows Ohm’s Law?
A resistor.
Does a filament bulb obey Ohm’s Law?
No, because its resistance changes as it heats up.
What happens to resistance in a diode?
It only allows current to flow in one direction.
What is the purpose of a resistor?
To control the amount of current in a circuit.
Why does a thicker wire have lower resistance?
It has more space for electrons to flow.
