8th Grade Science Released Tests

Both light bulbs are lit in the circuit above. In order to turn off both lights, a switch must be installed in the circuit at the place marked —
1. 1
2. 2
3. 3
4. 4
In order to turn on the light, a piece of wire needs to be connected from —
1. A to C
2. A to D
3. B to C
4. C to D
Which of the following is shown in this diagram?
1. Alternating current
2. Short circuit
3. Series circuit
4. Parallel circuit
Insulation materials reduce heat loss because they —
1. are poor conductors
2. block out the sun
3. reduce evaporation
4. promote convection
An electric light bulb is hot to the touch because —
1. current passing through it produces heat
2. its magnetic field produces a large amount of heat
3. evaporation causes an object to heat up
4. its chemical reactions produce heat
According to the data in the table, which sample of matter is most likely a metal?
1. 1
2. 2
3. 3
4. 4
In the diagram, what essential part of an electric circuit is missing at position X?
1. Load
2. On/off switch
3. Wires
4. Source of electric current
Electric bills are calculated based on the amount of energy consumed. The consumption is measured in units of —
1. newton meters
2. millijoule seconds
3. megavolt minutes
4. kilowatt hours
Which of the following is an example of static electricity?
1. A dry-cell battery connected to wires lights up a light bulb.
2. A balloon sticks to a wall after it is rubbed with a piece of wool.
3. A magnet sticks to a refrigerator door made of metal.
4. A light switch that is turned on runs a ceiling fan.
Objects with like charges repel and unlike charges attract. The girl’s hair and the comb have —
1. unlike charges
2. like charges
3. neutral charges
4. no charges
Laundry in a clothes dryer often becomes charged with static electricity while drying. Which of these best explains why a clothes dryer often generates static electricity?
1. Short circuits in the dryer charge the laundry.
2. Clothes with metal pieces conduct electricity in the dryer.
3. Electrons are transferred as clothes rub against each other in the dryer.
4. Heat from the dryer charges the air and produces lightning.
A mixture of iron filings and sulfur can easily be separated by —
1. placing the mixture in water
2. performing a chemical reaction
3. heating the mixture
4. using a magnet
Which of the following is a true statement about the magnetic field between two magnets?
1. The south pole of one magnet is attracted to the south pole of the other magnet.
2. The south pole of one magnet is attracted to the north pole of the other magnet.
3. The north pole of one magnet is attracted to the north pole of the other magnet.
4. The south pole of one magnet is attracted to both poles of the other magnet.
At which point is the magnetic field the strongest?
1. Point 1
2. Point 2
3. Point 3
4. Point 4

8th Grade Science Released Tests - Energy