Ohm's law (electricity) Flashcards
What is Ohm’s law?
Potential difference is directly proportional to the current through a conductor.
What is current, what is it measured in?
The rate of electric flow, measured in Amperes (A)
What is electric charge and what is it measured in?
Electric charge is the movement of electrons from negative to positive in a metal, measured in Coulombs (C)
What is the formula for the charge of flow?
Q = I x t
Electric flow = current x time
What is potential difference and what is it measured in?
How many joules of energy from the electrons is transferred for each flow of charge moving in a circuit. Measured in volts using a voltmeter.
Describe what a cell is in a circuit.
A source of electrons (a battery) that has a positive and negative end. It stores chemical energy which is then transferred as electrical energy as the electrons from it move through the circuit.
What is resistance and what is it measured in?
How much voltage is required to push a current through a conductor
How easy it is for electrons to flow through a conductor.
As electrons flow, they push through many vibrating atoms inside the wire which causes heat.
What formula links voltage, current and resistance?
V = I x R
Voltage (V) = current(A) x resistance (Ω)
In a series circuit how is an ammeter and voltmeter connected?
An ammeter is connected in series with the circuit as the current remains the same through it.
A voltmeter is connected in parallel as it can depend.
What formula connects voltage, energy transferred and charge?
V = E / Q
Voltage (V) = Energy transferred (J) / Charge (C)
How do you find the total resistance of a series circuit that has multiple resistors on it with different readings?
Add all values together.
What factors affect a wire’s resistance?
-Temperature
-Length of wire
-Type of material
-Thickness of wire
What is the correlation between resistance and energy.
The more resistance the more energy the circuit needs to push the current through.
What happens when two insulators rub against each other?
One insulator gains electrons (negative charge) and one loses electrons (positively charged)
What do all charged atoms have?
An electric field.
