Electric Charge
Where are protons, neutrons, and electrons found in an atom?
neutrons and protons are found in the nucleus, electrons are found in the electron cloud
What type of current is where the current changes direction regularly?
alternating current
If two of the same poles of two magnets are placed near each other, what type of force will they exert on each other?
repulsion
When an electric current flows through a wire, what does it create?
a magnetic field
What charge do electrons, protons, and neutrons have?
electrons-negative
protons-positive
neutrons-neutral
What type of circuit is where the components are on different branches?
parallel circuit
How is an n-type semiconductor made?
An n-type semiconductor is doped with an element with 5 outer electrons leaving a free electron which makes it negatively charged.
How is an electromagnet made?
A coil of wire is wrapped around an iron core and attached to a circuit
How can neutral objects gain an electrical charge
An electron moves from one object to another
If the voltage is 280 V and the resistance is 14 ohms, what is the current?
20 A
How is a p-type semiconductor made?
A p-type semiconductor is doped with an element with 3 outer electrons leaving a free space for an electron to fill which makes a positive charge
Explain how a magnet can induce an electric current.
by changing the magnetic field or moving a magnet along a wire
What type of energy is converted electrical energy for a battery, a thermocouple, and a photovoltaic cell?
battery-chemical energy
thermocouple-heat energy
photovoltaic cell-light energy
If the voltage is 250 V and the current is 18 A, what is the power?
4,500 W
Explain how a vacuum tube works.
When a current flows through the filament, it gives of heats and warms the electrode. The cathode gives off electrons when heated and the anode collects the electrons creating a flow of electrons through the vacuum tube. The flow of electrons is only able to move in one direction
How does a step-down transformer decrease the voltage?
the secondary coil has less loops than the primary coil
How does friction create an electrical charge?
Two objects rub together causing electrons to moe from one object to the other
If a refrigerator uses 1250 W and runs for 12 hours per day for 30 days, how much energy is used?
450 kWh
Explain how a telephone works.
There is a transmitter behind the mouthpiece that converts the vibrations from speaking into an electric current. The electric current is then sent through telephone wires to the receiver. The receiver, located in the earpiece, converts the changes in the amount of electric current back into sound using an electromagnet.
Explain how a simple generator works.
A coil of wires is wrapped around an axel that is between two magnets. When the coil of wire is rotated, it moves through the magnetic field inducing an electric current.