WorksheetsGrade 8 Electricity
Total questions: 35
Worksheet time: 23mins
How do television sets and computers cause allergies to be worse?
The static charge on the screens attracts particles of food that a person may be allergic to.
The sight of allergens on the television or internet may trigger an allergic reaction
The static charge that builds up on the screens attracts dust and accompanying dust mites and their feces, which are common allergens.
Electric forces within the devices trigger an allergic reaction. Allergies respond to charges.
The opposition to the flow of electric charge is called
(a)
Atoms that have gained or lost charge are called
ions
protons
electrons
neutrons
Objects with like charges will (a) .
The closer together charged objects are, the (a) the electric force is.
Friction transfers electrons when:
Friction can't transfer charge.
Two objects come close to one another and one produces a localized charge in the other
two objects remain separated and the charge has to jump from one to the other.
two objects are rubbed together, transferring charge from one to the other
The buildup of electric charge on an object is termed
television static
static cling
static electricity
static waves
Electrical conductors allow
charges to move freely
resistance to the movement of charges
charges to remain in place on an object.
the trains to run on time.
These materials are used to control the flow of charge because they conduct electricity better than electrical insulators but not as well as electrical conductors.
(a)
These materials include plastic and rubber and they do not allow charge to move freely
electrical conductors
electrical insulators
banks
semiconductors
An object can become charged by:
friction
friction, contact, or induction
direct contact with a source of atoms
induction
Charge affects electric force by the signs of the charges on the two objects and by
the amount of charge on each object.
how much mass the charged object has.
the temperatures of the charged objects
the color of the charged objects.
Objects with opposite charges will (a) .
The magnitude of electric force between two charged objects is related to:
charge and mass
mass and distance
charge and time
charge and distance
Electrons are assigned what charge
positive (+)
negative (-)
neutral (0)
no charge
A property that leads to electromagnetic interactions between the particles that make up matter is called:
electric avenue
electric charge
electric sign
electric company
Electric, gravitational, and magnetic forces are examples of
Forces that only act between objects in contact with each other
Forces that can do no work
Forces that do not have an associated direction.
Forces that can act on an object without being in contact with that object.
The rate of flow of electric charge is called:
(a)
The SI unit for electric current is the
joule, J
watt, W
newton, N
ampere, A
When an object loses some or all of its static charge because the electric charge travelled somewhere else, this is called:
electric charge
electric discharge
electric-in-charge
electric recharge
What does it mean that charge is conserved?
Electrons are lost
Charge is destroyed when it meets another charge of opposite sign
Charge lost by one object must have been transferred to another object
Charge does not flow
Atoms are composed of a positively charged nucleus that contains protons and neutrons. The negatively charged particles orbiting the nucleus are:
positrons
electrons
neutrinos
orbitals
The total amount of charge in the universe is always the
(a)
The type of current that flows in one direction and is used to power our cars, flashlights, and cameras is called:
direct current
indirect current
alternating current
dynamic current
The type of current that comes from the power company and is used to power most of our household appliances is called:
alternating current
direct current
indirect current
dynamic current
An example of an electrical conductor is
sulfur
copper
carbon
wood
The amount of work required to move each unit of charge between two points is called
(a)
If the voltage in a wire is increased, the electric current will
(a)
Voltage is equal to
current/resistance
current - resistance
current + resistance
current x resistance
Resistance affects electric current how?
Higher resistance at the same voltage results in higher current.
Higher resistance at the same voltage results in lower current.
Resistance lets the electric current flow more freely.
Cooler wires increase resistance and decrease the current at the same voltage.
Copper. Silicon. PVC plastic.
Low resistance <----------------------------------------->High resistance
Which material will slow the flow of electric charges the most?
(a)
What does it mean to say that the electric current from a wall socket in your house is "120 V AC"?
The socket provides amazing current at 120 volts.
The socket provides indirect current at 120 volts.
The socket provides alternating current at 120 amps.
The socket provides alternating current at 120 volts.
Renewable sources of electrical energy are:
coal and oil
wind, solar, and hydroelectric
wood and sand
natural gas and gasoline
The lemon battery has what kind of current?
alternating
indirect
direct
isolated
In direct current, voltage is
constant
alternating
low
high
