chapter 13 electricity!. quick review: conductors insulators like charges ___________ and unlike...
TRANSCRIPT
Quick review:
ConductorsInsulatorsLike charges ___________ and unlike
charges _____________.
Repel
Attract
An objects electric charge depends on the imbalance of it protons and electrons.
Objects can be charged by the transfer of electrons.
Charging by Friction, Conduction and ________________.
Electric Force = the force of attraction or repulsion between object due to charge.
Electric Force depends on charge and _______________.
Voltage and Current!
Volt is the SI unit for potential difference. (voltage) (V)
A cell is a source of electrical current because of the potential difference, or voltage, between the terminals.
A voltage sets a charge in motion. Example: Electrons move from the negative
terminal of a battery to the positive terminal when a flash is turned on.
*Conductors have low resistance*
Resistance is the ratio of voltage across a conductor to the current it carries.
Resistance is caused by internal friction and slows the movement of charges.
Resistance = Voltage/Current
Practice problemsThe heating element in an electric kettle
has a resistance of 30 Ω.
What is the current in the heating element when it is connected to a 230 V supply?
A circuit contains a 6 volt battery and a bulb with a resistance of 3 ohms. Calculate the current.
What is the voltage of a circuit with 15 amps of current and toaster with 8 ohms of resistance?
A circuit contains two 1.5 volt batteries and a bulb with a resistance of 3 ohms. Calculate the current.
You have a large flashlight that takes 6 D-cell batteries. If the current in the flashlight is 2 amps, what is the resistance of the light bulb? (Hint: A D-cell battery has 1.5 volts.)__________________
Electric Circuit: an electrical device connected so that it provides one or more complete paths for the movement of charges.
Schematic Diagram: a graphic representation of an electric circuit or apparatus with standard symbols for the electrical devices.