Electric Circuits

Electric CircuitsChapter 20.3

Key Concepts and VocabularyKey Concepts:What is included in a circuit diagram?

How do series and parallel circuits differ?

How do you calculate electric power and electrical energy used?

Vocabulary:Electric circuit

Series circuit

Parallel circuit

Electric powerCircuit DiagramsUse symbols to represent parts of a circuit.

Include:Sources of electrical energyDevices that are run by electrical energy

Circuit Symbols

Each battery = 1.5VTypes of Circuits

Series CircuitsCharge has only ONE path through which it can flow.

If one element stops functioning in a series circuit, NONE of the elements can operate.

The bulbs in a circuit are a source of resistance. The more bulbs, the more resistance.

Objects in SeriesVoltage is split equally among the resistors in the circuit.

Current is the same throughout the circuit.

-6V3V0V+Draw a diagram for this circuitWhat would the voltage be at each bulb if the total voltage is 9 V.

How could you make each bulb brighter

Parallel CircuitCharge has TWO OR MORE paths through which the charge can flow.

If one element stops functioning, the rest of the elements can still operate.

Lamps in Parallel

Draw a Circuit Diagram

Draw a Circuit Diagram

Which is a series circuit and which is parallel circuit?

ParallelSeriesIn which are the lamps in series and in which in parallel?

Power and Energy Calculations

PowerPower is the rate of doing work.Power is measured in WATTS (W).

Electrical PowerElectrical power is the rate at which electrical energy is converted to another form of energy.Electrical power is calculated by multiplying voltage by current. P (watts) = I (amps) x V (volts)

Electrical PowerElectrical power is calculated by multiplying voltage by current.

Power (P) = Current (I) x Voltage (V) (W)atts (A)mps (V)oltsPractice ProblemAn electrical oven is connected to a 240-volt line, and it uses 34 amps of current. What is the power used by the oven?

P = I x VP = 34A x 240 VP = 8200 WPractice ProblemsMath PracticePage 611Problems 1 3Page 613Problem 7 - 8

Electrical EnergyHow much energy is used by an appliance.

Energy = Power x Time

E = P x t

Unit = kilowatt-hoursThe power rating on an electric oven is 9300 watts. If the oven is plugged into a 240-volt line, how much current does it use? What is the resistance of the oven? If the oven is operated for 1 hour per day, how much electrical energy does it use per day.A freezer has a power rating of 105 watts. How much current does it use if it is plugged into a 120-volt line? If the freezer is used all the time, how much electrical energy does it use in a year?