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WorksheetsPHYSICS_GRADE 8_ELECTRICITY and HEAT TRANSFER
Total questions: 55
Worksheet time: 28mins
Which of the following is the best example of an electrical conductor?
tire
plastic
steel
none of the above
Electric circuit is a path for transmitting electric current
true
false
What is the main difference between parallel and series circuits?
in series circuit, charges flow multiple paths; charges in parallel circuit flow in one path
in series circuit, charges flow one path; charges in parallel circuit flow in multiple paths
in parallel circuit, several lamps work separately; in series circuit, several lamps work independently
in parallel circuit, if one lamp breaks then the other lamps will also off; in series circuit, if one lamp breaks then the other lamps still works
What kind of circuit is this?
series
parallel
A ______ opens and closes a circuit.
cell
conductor
wire
switch
What is this symbol for?
light bulb
wire
cell
battery
When you remove a bulb from a three bulb circuit, and the other two bulbs go off, then the bulbs must have been connected in parallel.
true
false
Electric current is the flow of _________.
protons
neutrons
electrons
none of them
Electric current is measured in....
watt
joule
newton
ampere
When one light bulb burns out, the rest stay lit. The bulbs must be found in ....
series circuit
parallel circuit
What kind of circuit is this?
series
parallel
Are the currents at A1 and A2 same?
Yes, they are same
No, they are different
What is voltage?
Voltage is the current per unit of time
Voltage is the energy per unit of charge
Voltage is power of resistance
Voltage is the total charge in the object
What is the unit for voltage?
ampere
joule
ohm
volt
120 Coulomb charge is flowing through wire in two minute. Calculate the electric current!
1 A
2 A
60 A
120 A
What is the relation between voltage and electric current?
V=R/I
V = I/R
V=R+I
V = IR
What is the relation between charge and electric current
Q = t / I
Q= I x t
Q = I / t
Q = I + t
12 Volt battery is used to turn on a light bulb. If the internal resistant of light bulb is 4Ω, Calculate the electric current!
2 A
6 A
3 A
48 A
This circuit is .....?
parallel
closed
open
shows the flow of electricity
When all parts of the circuit are connected, it is a ______ circuit.
open
closed
When you flip a light switch on and off you are closing and opening a circuit.
true
false
A circuit must be closed for electrons to travel.
false
true
What is the function of a switch in a circuit?
to make the current hotter or colder
turn on and off the flow of electrical current
the pathway that electrical current flows
to add more power to the circuit
Which of these best completes the circuit?
rubber band
metal nail
leather shoelace
wooden toothpick
Which of the following can supply energy in an electric circuit?
a conductor
a wire
light bulb
a battery
Look at the picture. Why won't the light bulb light up?
The wires from the light bulb are not connected to the battery
The switch is not closed to form a complete circuit
The wires from the light bulb are not connected to the switch
The wires from the battery are not connected to the switch
Pick the correct sentence.
This circuit will work because it is a closed circuit.
Energy will freely flow in this circuit.
This circuit will not work because there is no energy source.
This circuit will not work because there is no switch.
The circuits in this diagram are connected in series. In which diagram will the lights be the brightest?
They will all have the same brightness of lights
Circuit B will have the brightest lights
Circuit A will have the brightest lights
Circuit C will have the brightest lights
The two circuits shown in this diagram both have two lights connected in very different ways. In which diagram will the lights be the brightest?
Circuit B will have the brightest lights
Circuit A will have the brightest lights
They will both have lights of the same brightness
What would happen if an extra battery cell is added?
The lights will glow dim
The wire will glow
The lights will glow brighter
None of the above
What is Resistance?
The flow of electrons
A battery
Electric potential difference
The ability to reduce the flow of electrons
What is the Voltage of a circuit that has a resistance of 5 Ω and a current of 2 A?
25 V
10 V
2.5 V
0.4 V
If 6 C charge flows in 2 s time. what will be the value of current
3 C
3 A
12 A
12 C
How much time will it take to flow 8 C charge to cause a current of 2 A?
16 s
4 s
0.25 s
8 s
What is the transfer of heat by movement of liquids or gases?
Radiation
Conduction
Convection
Heat
What is a transfer of heat energy by electromagnetic waves?
Heat
Radiation
Convection
Conduction
What is the transfer of heat by direct contact?
Convection
Electromagnetic waves
Radiation
Conduction
What is the transfer of kinetic energy from one substance to another?
Energy
Temperature
Heat
Thermal energy
What is the energy of the movement of particles in a substance?
Potential energy
Temperature
Kinetic energy
Thermal energy
What is energy?
Kinetic
Movement
Ability to do work
Thermal energy
Walking on the hot sand on a beach
Conduction
Convection
Radiation
A Ceiling fan forcing the warm air downward.
Radiation
Conduction
Convection
Feeling heat from a campfire
Conduction
Convection
Radiation
Chocolate candy melting in your hand.
Convection
Radiation
Conduction
Heat from the hood of a car when you touch it
Convection
Conduction
Radiation
Feeling the heat from a stove burner without touching it
Conduction
Convection
Radiation
What is the definition of CONDUCTION?
When heat is transferred from objects like rays of light or electromagnetically.
a hot liquid or air that expands, becomes less dense, and rises or becomes more dense, and sinks.
When heat transfers through the heater or AC in your house.
When heat transfers from objects that are touching.
What is the definition of CONVECTION?
When heat transfers through waves.
When heat transfers from objects that are touching.
Heat traveling from the sun
a hot liquid or air that expands, becomes less dense, and rises or becomes more dense, and sinks.
Ironing a shirt is an example of...
condensation
radiation
conduction
convection
A chair is placed several feet from a fireplace. The fireplace has a glass screen. The side of the chair facing the fireplace gets warm because of ___________
conduction
convection
radiation
A huge boulder at the state park gets so hot during the day.
Convection
Conduction
Radiation
Why are metals useful for making electrical wire?
Metals do not bend.
Metals are insulators.
Metals hold much heat.
Metals are conductors.
The candle will slowly heat the metal and transfer the heat directly to the mans hand.
convection
radiation
conduction
In this experiment, the WARM red dye and the COLD blue dye was placed in the water at the same time. The warm red dye rose to the top while the cold blue dye sank to the bottom.
conduction
convection
radiation
Which is NOT an insulator?
Wool
Plastic
Copper
Glass
