IPC Notes

Electric Current & Electricity Calculations

Electric Current

electric current – the flow of electrons through a conductor

resistance – the tendency of an object to resist the flow of electrons

Closed vs. Open Circuits

closed circuit – allows the flow of electricity; the circuit is complete

Closed vs. Open Circuits

open circuit – prevents the flow of electricity; the circuit is incomplete

Batteries

battery – uses voltage differences to create a flow of current

2 Types of Batteries

dry cell battery – uses a chemical paste surrounding a carbon rod

ex) AA battery

2 Types of Batteries

wet cell battery – uses 2 types of metallic plates suspended in a conducting solution

ex) car battery

Electricity Calculations

V = I x R

V = voltage (volts)I = current (amps)R = resistance (Ohms)

Electricity Calculations

P = I x V

P = power (watts)I = current (amps)V = voltage (volts)

Electricity Calculations

E = P x t

E = energy (kilowatt hours)P = power (kilowatts)t = time (hours)

Practice Problem #1How much power is used by a light bulb if it uses a current of 1.2 amps and a voltage of 120 volts?

Practice Problem #2What is the resistance of an appliance that uses 0.89 amps when the voltage is 120 volts?

Practice Problem #3How much current is flowing through a wire with a 4.5 ohm resistor and a 6 volt battery?

Practice Problem #4How much power is used if 350,000 kilowatt hours of energy are used in 58 hours?

Practice Problem #5What is the voltage of a battery if 4.5 watts are used with 0.5 amps of current?

Practice Problem #6How long does it take a 2 kilowatt appliance to use 36.5 kwh of energy?