Electricity and Magnetism Flashcards
What is Coulombs law?
Opposite charges attract one another and like charges repel one another
What is current electricity?
The ability for electrons to hop from one atom to another.
What is an electric current and how is it measured?
Measures the number of electrons that flow past a particular point in a circuit per second
Measured in amps (A) and represented by variable I
Can be measured using an ammeter
What is electric potential difference and how is it measured?
Measures the rise or drop in electric potential as a current moves through a component of the circuit
Measured in volts (V) and represented by variable V
Measured by a voltmeter
What is ohm’s law?
The potential energy difference across the component is directly proportional to the electric current flowing through it, as long as the temperature is constant
How do you calculate resistance?
R = V/I
R: resistance in ohms (Ω)
V: electric potential difference in volts (V)
I: electric current in amps (A)
Explain the difference between electron flow and conventional flow.
Electron flow: electrons move away from the negative terminal and towards the positive terminal (this theory is based on type of charge, negative or positive)
Conventional flow: electrons flow from the positive charge to the negative charge (based on amount of charge, positive has a higher amount of charge whereas negative has a lower amount of charge)
What is the difference between alternating current and direct current?
In AC the electrons move back and forth continuously
In DC the electrons move in one general direction, from negative to positive
What is Kirchhoff’s Current law? How is it affected by series vs parallel circuits
KCL states that current into a junction point (where more than 2 wires meet) in a circuit must equal the current out of the junction
In a series circuit, current remains constant
In a parallel circuit, the current leaving the power source = the current entering the power source but the current can be split at junctions, but the current that enters the junction = the current that leaves the junction (total current = sum of all currents)
What is Kirchhoff’s Voltage Law? How does it differ for series circuits and parallel circuits?
KVL states that the total rise in electric potential must equal the total loss in electric potential along any complete path in an electrical circuit
In a series circuit, the voltage produced is the same amount of voltage lost in the circuit. total V = V1 + V2 + V3
In a parallel circuit, voltage remains constant when resistors are in parallel
- Parallel paths are not considered the same path
How do you calculate resistance in a series circuit?
Total resistance is the sum of all of the resistances throughout the circuit.
How do you determine the north and south poles of a magnet?
North pole naturally faces the north pole, south pole naturally faces the south pole
What is the Law of Magnetic Poles?
Opposite poles attract, like poles repel
What are the 5 important points relating to Magnetic field lines?
Magnetic field lines flow away from north and towards south
Magnetic field lines are continuous loops
Magnetic field lines are 3 dimensional
Magnetic field lines get weaker further from the magnet
Magnetic field lines cannot cross over one another
What is Oersted’s principle?
Current moving through a conductor creates a magnetic field
Magnetic field lines are perpendicular to current flow
