Intro (23-07-18) Flashcards
Which direction is conventional flow?
+ve to -ve
Which direction is electron flow?
-ve to +ve
What is the power equation?
P = I x V
what is ohms law?
V = I x R
What kind of voltages are used on light A/C?
14V DC
What kind of voltages are used on large A/C?
28V DC for small controllable loads
115V AC for larger loads
What is current?
electron flow
What is voltage?
electrical pressure
What is resistance?
resistance to current (DC circuits only)
What is impedance?
AC circuit resistance
What is inductance?
generation of electron flow
What is reactance?
resultant effect of inductance or capacitance
What is capacitance?
ability to store charge
What are 6 ways to provide EMF to move electrons?
friction - static electricity
chemical action - cells and batteries
magnetism - generators and alternators
heat - thermocouples
light - photo electric cell
pressure - piezo electric crystals
What is the equation for the force created by a current flowing through a length of wire in between the poles of a magnet?
F = B x L x I
B - flux density
L - length of wire in meg field
I - current
What is the unit used to measure capacitance?
farad
usually in the magnitude of millifarad
How do you calculate the overall resistance of resistors in series?
add them together
How do you calculate the overall resistance of resistors in parallel?
1/Rt = 1/R1 + 1/R2 + etc
What 3 factors determine the capacitance of a capacitor?
area of plates
distance between plates
dielectric constant of dielectric
What is the equation for calculating the capacitance of a capacitor?
c = q / v
q - charge
v - voltage
