Electricity and Circuit
What is the total displacement of a student who walks 3 blocks east, 2 blocks north, 1 block west, and then 2 blocks south?
2 blocks east
What describes the function of a battery in a simple electric circuit?
It pushes electrons through the circuit
How would decreasing the diameter of the wires in a circuit influence the resistance and flow of electrons in the circuit?
It would increase the resistance, causing fewer electrons to flow through the circuit
The opposition to the flow of electrons
Resistance
When an uncharged balloon is rubbed against dry uncharged hair, electrons move from the hair onto the balloon's surface. Which table lists the charges of the balloon and the hair after they are moved apart?
The ballon is negative The hair is positive
A battery is connected to a light bulb with copper wire to complete a circuit. The bulb immediately lights. Which of the following statements best describes why the light bulb lights?
The battery supplies voltage, which causes electrons throughout the circuit to move
In this circuit there are three light bulbs connected to the same battery. If one of the bulbs blew, what would happen to the other bulbs?
The bulbs would continue to work
The difference in electrical potential energy between two places in a circuit
Voltage
Which of these is necessary to make a closed circuit?
a closed path
This provides a safe, conductive path to the Earth.
a ground
A doorbell contains a simple electromagnet. Which change would most likely increase the strength of an electromagnet?
a larger power source
Which is a true statement about a series circuit? a. all of the current flows through every part of the circuit. b. every part of the circuit is positively charged c. the current through the circuit can take several paths. d. every part of the circuit is negatively charged.
a. all of the current flows through every part of the circuit.
This term measures the amount of current flowing through a circuit.
ampere
Which change would decrease the strength of the electromagnet? a. using an additional battery b. using fewer wire coils around the nail c. using more wire coils around the nail d. using an iron nail
b. using fewer wire coils around the nail
A path through which electrons can flow
closed circuit
Charging by contact
conduction
This type of material has a low resistance in an electrical circuit.
conductor
The continuous flow of electrons through a conductor
current
Which change to the electromagnet would produce the strongest magnetic field? a. 1 battery and 2 coils of wire b. 1 battery and 20 coils of wire c. 2 batteries and 2 coils of wire d. 2 batteries and 20 coils of wire
d. 2 batteries and 20 coils of wire
Which of the following actions would increase the current through a circuit component? a. increasing the resistance of the component b. placing another identical component in a series in the circuit c. decreasing the power in the component d. increasing the voltage across the component
d. increasing the voltage across the component
What would not increase the resistance in a circuit?
decrease the length of the wire
If the diameter increases, resistance ______________
decreases (the bigger the diameter the better conductor)
The part of the atom that is negatively charged
electron
When a plastic rod is rubbed with wool, the wool acquires a positive charge because
electrons are transferred from the wool to the rod
Examples of an insulator
glass, plastic, wood
This term means providing a safe path of excess electric charges to the Earth.
grounding
Charging by causing a separation of charge in a neutral object without touching it
induction
This type of material has a high resistance.
insulator
A static discharge differs from an electric current in that a static discharge______________.
lasts for only a fraction of a second
To increase the brightness of a desk lamp, a student replaces a 60-watt light bulb with a 100-watt light bulb. compared to the 60-watt bulb, the 100-watt bulb has
less resistance and draws more current
The part of the atom that is neutral
neutron
This term measures the resistance in a circuit.
ohm
An electrical circuit that is not complete
open circuit
This type of circuit maintains multiple paths for electrons to flow.
parallel
Current travels in multiple paths and one break will not stop the flow of electrons.
parallel circuit
Examples of a conductor
penny, nail, key
The part of the atom that is positively charged
proton
This type of circuit has only one path for the current to travel.
series
Wires and devices connect to form a single pathway for electrons to flow. One break in the path will stop the flow of electrons.
series circiut
A student wants to build a simple circuit. Which material would be used to design a circuit with the least amount of resistance?
short wires with a large diameter
What will happen when two objects with opposite electric charges are moved closer together?
the objects will attract each other with a greater force
A student connects three identical light bulbs in a parallel to a dry cell as shown below. What happens when the student removes one of the light bulbs from its socket?
the other light bulbs remain on and will be equally bright.
A charged rod attracts a piece of neutral paper. What conclusion can be made?
the rod can be either negative or positive
Where would the electrons in this electroscope go if a positive rod came near and it experienced induction?
the top of the electroscope
What is the purpose of a battery in a circuit?
to provide voltage
Potential Difference is the same as ___________
voltage
