Electrostatic & Electrodynamics Flashcards
What is voltage?
Electromotive force (potential diffence)
V=?
V = E/Q (energy/charge)
V = lR ( current • resistance)
Unit of voltage
Volts (v)
Unit of energy
Joules ( J )
Unit of charge
Coulombs (c)
Unit of current
Amps (A)
Unit of resistance
Ohms (omega)
What is current?
Rate of flow of electrons
I=?
I= Q/t ( charge / time )
I= V/R
Unit of time
Seconds (s)
What is resistance?
Opposition to the flow of electric current
R=?
R= V/I
What is electrical power?
Rate at which energy is transferred in a circut
P=?
P= E/t (energy/time)
P= IV (current • voltage)
Unit for power
Watts (W)
What is coulombs law used for?
Calculating the force between 2 charged particles
What happens when you get a positive value when calculating using coulombs law?
Particles repel eachother (as they were either both positive or negative)
What happens when you get a negative value when calculating using coulombs law?
Particles attract (since one is negative & one is positive)
Formula for coulombs law, F =?
F= Ke( (Q1 • Q2) / r^2 )
F= force
Ke= Coulomb’s constant
Q1= charge of particle 1
Q2= charge of particle 2
r= radius
R=?
Mnemonic
R= roh ( L / A )
R= resistance
Roh= resistivity
L= length
A= area
Replay
What is the opposite of resistance & resistivity?
Conducting & conductor
Symbols for resistor
Google answer
Symbols for battery/power supply
Google answer
Symbols for voltmeter & ammeter
Google answer
What is Kirchhoff’s first law?
Total current entering a junction = total current leaving the junction
What is Kirchhoff’s second law?
The direct sum of the potential differences (voltages) around any closed loop is zero
If 1 thing in series circuit stops working what happens?
The whole circuit will stop working
What happens to voltage in a series circuit?
It is shared across the components
What is current in a series circuit?
Constant (identical across elements)
What is the total resistance in a series circuit?
Sum of all individual resistances
What happens to a parallel circuit if 1 loop breaks?
Circuit still remains in tact
How is voltage distributed in parallel circuits?
All components in each loop get the full voltage
How is current distributed in parallel circuits?
It is shared between the loops
What happens to the total resistance of a parallel circuit when we add more loops with components?
The total resistance decreases
Formula for calculating total resistance for resistors in parallel
1 / R =1/R1 + 1/R2….
Will resistance of a wire increase if voltage is increased?
No it is an inherent property
What happens to the magnetic field when the wire is wrapped into a coil?
It becomes stronger
What happens to electromagnetic field of a wire coil when current is increased?
Magnetic field increases
What kind of current is generated when a magnet is passed through a wire coil in one direction?
The amp meter shows a current is generated, a dc current
What kind of current is generated when a magnet is passed through a wire coil in alternating directions?
The current alternates direction and ac current is generated
What happens to the current when moving the magnet faster?
Current is stronger
What happens to the current when using a stronger magnet?
Current also increases
What happens to the current when using a larger coil with more turns?
Current gets stronger
What can be adjusted when using an electromagnet?
The current & voltage to vary the strength of the magnetic field & the induced current
Easy way to create a current in a coil?
Rotating a magnet & placing the coils around it
Where is the strongest part of the magnetic field on a magnet?
At the ends where the magnetic field lines converge
