Chapter 27 Formulae Flashcards
(13 cards)
How do you find the period of rotation (time)?
1/Frequency
What is the formula for drift speed?
(e tau E)/m
charge multiplied by time constant and E-field over mass of electron
What is the formula for electron current?
ne vd A
Conduction-electron density of material times the drift speed times the area of the wire segment
Why are current and electron current opposite directions?
Current does not account for the fact that most charge carriers are ELECTRONS. Therefore, current is the direction of the flow of POSITIVE charges.
A fully charged capacitor acts as what in a circuit?
It acts like an open circuit
What is the FIRST thing to take note of when finding electric or magnetic field?
Is the charge POSITIVE or NEGATIVE
What is the formula for conductivity?
(ne e^2 tau)/m
conduction-electron density of material times charge squared times time constant divided by mass of electron
What is the unconventional formula for Number of Electrons?
ie Δt
electron current times time (electron current refers to the number of electrons passing a point)
What is the relationship between two circuit elements that start and end on the same junctions?
They are in parallel
Batteries have no effect on what when using loop law?
They have no effect on CURRENT. IE, if the current before the battery is known, that current exists after the battery too
Formula for spring force?
Fs = KΔX
Properties of Series circuits
Voltage: Sum (Loop law)
Current: Same (NOTE: CHARGE is also same)
Resistance: Sum
Capacitance: Inverse sum
Properties of parallel circuits
Voltage: Same
Current: Sum (Junction law)
Resistance: Inverse Sum
Capacitance: sum
