SERIES & PARALLEL CIRCUITSElectric Power and Energy
SERIES CIRCUIT:-There is only ONE PATH forthe electrons to take betweenany two points in the circuit.*There will be no alternativeroute.-Has more than oneRESISTOR. Since there is onlyone path for the current totravel, the current through eachof the resistors is the same.*Resistors are components thatare used to control the amountof current flowing in a circuit.
PARALLEL CIRCUITS:-Two or more components areconnected between the sametwo points.- Has more than one resistorand gets its name form havingmultiple paths to move along.* Charges can move throughany of the several paths. Ifone of the items in the circuit isbroken, then no charge willmove through that path. Butother paths will continue to havecharges flow through them.
RECAP! SERIES CIRCUIT PARALLEL CIRCUITDESCRIPTION If one the items in the If one of the items in circuit is broken, then the circuit is broken no charge will move then no charge will through the circuit move through that because there is only path, but OTHER ONE PATH. PATHS will continue to have charges flow through them.RESISTOR As more resistors are As the number of added, the overall resistors increases, current in the circuit the overall current decreases. also increases.
EQUIVALENT RESISTANCE-Is the amount of resistance that a single resistorwould need in order to equal the overall effect ofthe collection of resistors that are present in thecircuit.RESISTORS IN SERIES:Two resistances are connected in series if allthe current from one resistor must flow throughthe second; there is no alternative route.
Equivalent resistance: From conservation of I1 = I2 = I charge: where I is the current through the combination. From conservation of V1 + V2 = V energy: where V is the potential difference across both resistors. The two resistors can be replaced by a single resistor with the equivalent resistanceFor more than two resistors, Req = R1 + R2 + R3 + ...
RESISTORS IN PARALLEL: - Two resistors are connected in parallel if theyare joined at both ends such that the potentialdifference across both resistors is the same. Thecurrent splits, flows through the two resistors, thencomes back together with no alternate path.
Equivalent resistance: From conservation of I1 + I2 = I charge: From conservation of V1 = V2 = V energy:The two resistors can be replaced by a singleresistor with the equivalent resistance Req:For more than two resistors:
RECAP! SERIES CIRCUIT PARALLEL CIRCUITThe total resistance of the The inverse of the totalcircuit, also called effective resistance of the circuit, isresistance is equal to the equal to the sum of thesum of the individual inverses of the individualresistances. resistances. R = R 1 + R2 + R3 + … 1/R = 1/R1 + 1/R2 + 1/R3 + …
ELECTRIC POWER AND ENERGYElectric Power:- Represents the rate at which energy isconverted from the electrical energy of themoving charges to some other form.- The SI unit of power is watt.Electric Energy:-Represents the presence and flow of an electriccharge. The energy portion of electricity is foundin a variety of phenomena such as staticelectricity, electromagnetic fields and lightning.-Consumption of electrical energy is measuredby Watt x Hour (Wxh)* 1Wh = 3600 joule = 859.8 calorie
ELECTRIC METER -An instrument that measures the amount of electric energy by a consumer. -The meter is calibrated in kilowatt – hours. 4 6 3 7 2When the hand of one of the dials is between numbers, always take thesmaller number. you cannot tell if a hand is past a number or not, simplylook at the dial to the right. If it has passed zero, then the hand ispointing to the correct number. If the dial to the right has not passedzero, then use the next smaller number.