PHYSICAL SCIENCE 8th GRADE
3rd NINE WEEKS PRE- TEST
For all math problems, use scratch paper. Do NOT write on the exam. This material will be taught in this 9 weeks, so you are not expected to know it all. Try your best and remember, DO NOT leave anything blank – guessing will not hurt you.
1. Iggleby the Alien used electromagnetic wave energy from the nearby sun to power his spaceship as he traveled from planet to planet in his solar system. He could use most types of electromagnetic energy. However, he could not use sound wave energy to power his ship because?(S8P4.d)
a. sound is a mechanical wave and cannot travel in space.
b. the frequency of sound waves won’t let him travel to the planets fast enough.
c. the pitch of the sound waves do not have long enough wavelengths.
d. sound waves can’t vibrate fast enough to give a spaceship power.
2. A compass needle responds to a magnetic field, because the compass needle is a: (S8P5)
a. transformer.
b. generator.
c. motor.
d. magnet.
3. The direction a transverse wave travels is(S8P4.a)
a) the same direction as the disturbance that caused the wave.
b) toward the disturbance that caused the wave.
c) from the disturbance that caused the wave, downward.
d) at right angles to the disturbance that caused the wave.
4. Which statement describes the relationship between frequency and wavelength of a wave?(S8P4.a)
a) When frequency increases, wavelength increases.
b) When frequency increases, wavelength decreases.
c) When frequency increases, wavelength stays constant.
d) When frequency increases, wavelength changes unpredictably.
5. As you increase amplitude of a wave, you also increase the(S8P4.f)
a) frequency.
b) wavelength.
c) compression.
6. How is the interaction between two magnets different from an interaction between a magnetand a magnetic metal?
(S8P5.c)
a.Two magnets always attract each other, while a magnet and a magnetic metal repeleach other.
b.Two magnets may attract or repel each other, while a magnet and a magnetic metalonly attract each other.
c.Two magnets may attract or repel each other, while a magnet and a magnetic metalonly repel each other.
7. Which of the following statements is trueabout rubbing a balloon against objects?(S8P5)
a.An electrically-charged object can attract objects that are oppositely charged
b.Electrically-charged objects have to be touching in order to interact with each other.
c.An electrically-charged object always attracts other chargedobjects.
d.An electrically-charged object always repels other charged objects.
8. Which of these changes to this series circuit wouldcause the electric current in the circuit to increase?(S8P5.b)
a.Add more bulbs in the series circuit.
b.Unscrew one of the bulbs in the loop.
c.Add more batteries in the series circuit.
.
9. Harold is an electrician wiring a house in Cartersville, Georgia. He prefers using copper wire to connect power,
outlets, switches, etc. to each other. Why does he prefer copper?(S8P5)
a.Copper is an electrical insulator and protects people from very high voltage.
b. The copper color is easier to find than other colors when repairing bad wiring in the walls later on.
c. Copper melts down if the electric current gets too high, which protects the house from fires.
d.Copper is an excellent electrical conductor and is an economical choice for carrying power to all the electrical devices
.
10.You want to install a burglar alarm in your house. Which of the following circuit would be appropriate for detecting if a window was to be opened?(S8P5.b)
a. a parallel circuit
b. a closed circuit
c. an open circuit
d. a series circuit
11. Thomas set up an experiment to find out which of theses substances-- water, cool air, hot air, or steel-- would let sound waves travel the fastest. A smart-aleck classmate came up, saw what Thomas was doing, and told him immediately what the correct answer was. Thomas’s experiment was spoiled! What did the classmate tell Thomas?(S8P4.e)
a) “Sound travels fastest through water because liquids are so smooth, the sound waves flow fastest.”
b) “Sound travels fastest through cool air because the colder something is, the faster and clearer sound can travel.”
c) “Sound travels fastest through hot air because the hotter anything is, the more it makes sound waves speed up.”
d) “Sound travels fastest through steel because solids have more particles in them to act as a medium.”
12. Manuel is a toll collector, taking up money on Highway 400 north of Atlanta. Read the line graph showing freeway noise levels at his booth. If ear protection should be worn for a sound level above 90 dB, when should Manuel start wearing hearing protection?
13. Two people are singing at the same pitch, what could be said of their frequencies? (S8P4.e)
a) Their frequencies are very similar, but the wavelengths are different.
b) Their wavelengths are similar but the frequencies are different.
c) Their wavelengths and frequencies are similar.
d) Their amplitude and frequencies are different.
14. Yoshie was about to perform an experiment, but she tied back her long hair first. What’s the best reason
why?(S8CS2)
a.So her hair would stay out of her eyes.
b.She wanted to look pretty around her lab partners.
c.Loose hair might fall into the experiment, getting into chemicals or catching on fire.
d.Her hair needed washing and she didn’t want anyone to see how greasy it was.
15. Increasing the number of loops per meter in the coil of an electromagnet is one way to: (S8P5.c)
a. increase the wire’s electric current
b. decrease the wire’s electric current.
c. strengthen the electromagnets magnetic field.
d. weaken the electromagnets magnetic field.
16. What are the invisible lines around a magnet called?(S8P5)
a. the areas called domains
b. the magnetic field lines
c. the magnetic forces
d. the north and south poles
17. When particles from solar explosions on the sun hit the earth’s magnetic field, where does most of
the interaction take place?(S8P5.c)
a. at the poles
b. at the equator
c. in the lithosphere
d. in the mantle
18. What would you measure to determine a wave’s frequency?(S8P4.a)
a) the distance from the crest to trough
b) its height from the crest to its resting point
c) how often a compression crosses a fixed point
d) the distance between adjacent crests
19. Why are protons and electrons attracted to each other?(S8P5.a)
a. because protons have a positive charge and electrons have a negativecharge
b. because protons have a negative charge and electrons have a positivecharge
c. because they both are positively charged
d. because they both are negatively charged
20.When Andre plugs his stereo into the same outlet as the television and lamp, all three won’t work. What is the
most likely hypothesis for what happened?(S8CS9, S8P5.b)
a.The circuit was overloaded, and the circuit breaker opened.
b.The circuit was complete, and the circuit breaker closed.
c.Only the stereo operates on alternating current.
d.The stereo’s electrical cord was faulty.
21. Joe was reconnecting two wires on a circuit while the power was still on. Which answer best explains why he did
NOTget a shock?(S8P5)
a. because the copper wire is a good insulator
b. because the plastic covering around the wire is a good insulator
c. he was lucky and should have turned off the power
d. his body acted as a conductor and the current flowed through him easily
23.You have just taken your clothes out the dryer and notice that they are sticking together. Which answer best
explains why?.(S8P5)
a. a build up of electric discharge
b. a build up of static electricity
c. a build up of electric current
d. a build up of heat
24.Which of the following is a property of a magnet?(S8P5)
a. they have two poles
b. they exert magnetic force
c. the have magnetic fields
d. all of the above
25.A scientist measured the distance between two positively-charged objects and determined the electric force
between them. Based on the data in the table below, which of the following statements is true?(S8P5.a)
a.As the distance between the objects increases,
the size of the electric force decreases.
b.As the distance between the objects increases,
the objects become more positively charged.
c.The size of the electric force is constant (doesn’t
change).
d.As the size of the objects increases, the size of the
electric force between them decreases.
26. Suki can have all five appliances in her kitchen on at the same time, or she can have each appliance on one at a
time. How are the appliances in Suki’s kitchen wired?(S8P5.b)
a.in a single loop
b.in a direct current circuit
c.in a parallel circuit
d.in a series circuit
27.If the direction of the electrical current is reversed on an electromagnet, what will happen to the
magnetic poles?(S8P5.b)
a. they will switch
b. they will stay the same
c. they become stronger
d. they become weaker
28. What makes a parallel circuit different from a series circuit?(S8P5.b)
a.A parallel circuit has more than one switch in the loop.
b.A parallel circuit only has one path for the electrical current to pass
c.A parallel circuit has two or more bulbs in it.
d.A parallel circuit has more than one pathway for the electrical current to pass.
29..Electrical generators transform one form of energy into electrical energy. Which answer best explains how generators transform energy?(S8P5.c)
a. from light to electrical
b from potential to kinetic
c. from mechanical to electrical
d. from electrical to mechanical
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30. Tyrone made a wave using a rope. The wave had alternating high points and low points. What are the high and low points called?(S8P4.f)
a) valleys and hills
b) rarefactions and compressions
c)dips and peaks
d) crests and troughs
31. With regard to hearing, what it the function of the middle ear?(S8P4.c)
a) carries vibrations from the eardrum to the inner ear
b) sends electrical signals to the brain
c) acts like a satellite and receives sound waves
d) increases the pitch of a sound wave
Picture a tub filled with water, with a toy boat floating on the water. You plunge your fist into the
water, next to the toy boat.(S8P4.a)
32. What will happen to the boat?
a) It will sink.
b) It will move up and down.
c)It will not move.
d) It will travel straight to the other end of the tub.
33. What will happen to the surface of the water?
a) Waves will move out from the disturbance.
b) The water will remain calm.
c)A wave will move from the surface to the bottom of the tub.
d) The water level will go down.
34. John and his son Andrew were spending the day fishing off the ocean pier at Tybee Island, Georgia.
Andrew began counting the waves as they passed under the end of the pier. He told his father that he
counted the same number of waves pass every ten seconds. What was Andrew actually measuring?(S8P4.a)
a) wavelength
b) frequency
c)speed
d) amplitude
35. A wave has a low speed but a high frequency. What can be said about its wavelength? (S8P4.a)
a) The distance of a wave will vibrate from its resting point.
b) The wavelength will be very long.
c)It depends on how fast the speed is.
d) The wavelength will be short.
36. Gabriel is standing on a street corner as an ambulance approaches. As the ambulance gets closer, the
pitch of the sound waves is high. Then, as the ambulance passes and moves farther away, the pitch
gets lower. Based on this information, what do the sound waves from the siren have when the
ambulance is being driven toward Gabriel?(S8P4.e)
a) the same frequency
b) a higher frequency
c)a decreasing frequency
d) a lower frequency
37. When will you hear the sound of a jet plane breaking the sound barrier? (S8P4.e)
a) When it happens.
b) When the barrier reaches the tail of the jet.
c) When the sound reaches your ears.
d) Exactly ten seconds after it happens.
38. Musical sound waves are what type of waves?(S8P4.a)
a) compression (longitudinal)
b) transverse
c) electromagnetic
d) ocean waves
39. What type of animal uses echolocation for hunting and navigation?(S8P4.e)
a) frog
b) elephant
c)bat
d) lemur
40. Sound travels fastest through(S8P4.d)
a. a vacuum (empty space).
b. air.
c. wood.
d. fresh water.
41. You are listening to a radio station and your favorite song is playing. You decide that you want to turn up the sound. What are you actually doing?(S8P4.f)
a. increasing the pitch of the sounds you hear
b. increasing the frequency of the sound you hear
c. increasing the wavelength of the sounds you hear
d. increasing the amplitude of the sound you hear
42. You are building a concert hall. You ask for advice about getting rid of the echo in the hall. The engineer most likely told you what?(S8P4.e)
a. hang smooth wooden planks on the walls
b. paint the walls
c. make sure the floors are hard wood
d. hang thick decorative cloth on the walls
43. Jessie walked into a large, dark room and yelled “Hello!” She heard a loud echo of the word almost immediately. Which of the following is a valid, true conclusion that Jessie could draw from her observations?(S8P4.e)
a. She produced sound waves that demonstrated the Doppler effect.
b. She produced sound waves that created a sonic boom.
c. She produced sound waves that destructively interfered with each other.
d. She produced sound waves that reflected off the walls of the room.
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