CURRENT ELECTRICITY Flashcards
What is current?
The rate of flow of charge
What is the equation linking charge, current and time?
current (I) = charge (Q) / time (t)
What is voltage/potential difference?
The energy transferred per unit of charge.
What is the equation linking energy, voltage and charge??
voltage (V) = energy transferred (E) / charge (Q)
How do we measure current?
Ammeter (in series)
How do we measure voltage?
Voltmeter (in parallel)
What does Ohm’s law state?
That the voltage is proportional to the current for a component with a fixed resistance.
What is the equation linking current, voltage and resistance?
V=IR
How does length affect resistance?
The longer the wire, the greater the resistance, because there is a greater number of collisions involving the delocalised electrons
How does the thickness of a wire affect the resistance?
The thicker the wire the lower the resistance, therefore increasing the number of pathways for the delocalised electrons.
How would temperature affect the resistance?
The higher the temp, the higher the resistance as ions can vibrate more, increasing NO. collision.
