intro to electrical circuits week 1

what is the symbol for a power source in an electrical system?

what is the symbol for an inductor in an electrical system?

what is the symbol for a resistor in an electrical system?

what is the symbol for a capacitor in an electrical system?

Bottom line can be bent

what is the function of an inductor?

regulates the current

what is the function of a capacitor?

stores and regulates the voltage

what is the symbol for a dc motor in an electrical system?

what is a battery analogous to in a fluid flow system?

pump

what are conductors (wires) analogous to in a fluid flow system?

frictionless pipes

what is an electrical current analogous to in a fluid flow system?

flow rate of fluid

what is the voltage analogous to in a fluid flow system?

pressure differential between points

what are the switches analogous to in a fluid flow system?

valves

what is the resistance analogous to in a fluid flow system?

constriction in flow, which produces turbulence and heat

what is crucial in an electrical circuit?

at least one power source and resistance

what letter is used to denote current?

i

does a positive (+) current follow the direction of the arrow?

yes

does a negative (+) current follow the direction of the arrow?

no

current units

Amperes (A) or Coulombs per second (C/s)

i(ab) = ?

-i(ba). the minus only implies direction. you cannot have a negative current

what letter denotes voltage?

v

what is the definition of voltage?

energy transferred per unit charge

units of voltage

Volts (V) or Joules per Coulomb (J/C)

what is the significance of the polarities (+ and - signs)?

denotes direction (ie supplier → absorber, source → load, etc)

v(ab) = ?

-v(ba)

what is the definition of a node?

a point where two or more circuit elements are joined together

what is kirchhoff’s current law?

all currents flowing into a node are equal to all currents flowing out of it

using kcl, why is i(3) = i(4)?

when in series, the current will always remain the same

what happens when there are more than one node side by side?

they are counted as one node

what is the definition of a loop?

a closed path starting from a node that traces all elements and terminates back at the starting node

what is kirchhoff’s voltage law?

the sum of all voltages in a looped path equals to zero

determine the signs of the voltage using kvl:

-v(a) + v(b) + v© = 0