Electricity and Magnetism Posttest

CDHOOD

1. Convert to meters: 6.7 decameters

A.670 metersB.6,700 metersC.0.67 metersD.67 meters

2. What is the reading shown on the triple beam balance below?

A.313.6 gB.310.6 gC.310.3 gD.424.6 g

3. Examine the table below. If the trend in the below table continues in the future, what do you think will happen?

A. Manufacturers will stop producing DVDs.B. VHS tapes will eventually not be sold anymore.C. The sales of DVDs will go down.D. The sales of VHS tapes will pick up.

4. Alexis was interested in the way mirrors reflect. The living room of Alexis' house had one big window in the front, and a very large mirror on the back wall. Alexis hypothesized that the room would heat up faster in the morning with the mirror

on the wall than it would if the mirror were covered with a sheet that was the same color as the walls. What will make Alexis' hypothesis valuable?

A. It will be valuable only if it is proved correct.B. It cannot be valuable because the investigation is in her house and not in the science lab.C. It will be valuable only if it is proved incorrect.D. Any testable hypothesis is valuable.

5. As the masses of two objects increase, how does the gravitational force between the two objects change?

A. The gravitational force increases.B. The gravitational force stays the same.C. The gravitational force decreases.D. The gravitational force begins to repel the objects.

6. Two negatively charged particles are placed close together. Which of the following best describes their interaction?

A. They will attract each other.B. They will repel each other.C. They will become magnetic.D. They will remain the same distance apart.

7. What holds a moon in its orbit?

A. the gravitational pull of the planet it orbitsB. its own internal magnetismC. the heat generated by the planet it orbitsD. the gravitational pull of the star it orbits

8. Which of the following objects exerts gravitational force?

I. the SunII. the EarthIII. the Moon

IV. a basketballV. an apple

A.IV and V onlyB.I, II, and III onlyC.I and II onlyD.I, II, III, IV and V

9. What will happen to the second light bulb if the first light bulb burns out?

A. It will also go out.B. It will get brighter.C. It will explode.D. Nothing will change.

10. To complete an electrical circuit, there are a few necessary elements. An electrical circuit can demonstrate energy flow even if it is

missing ________.

A. a receiverB. a switchC. a power sourceD. connecting wires

11. Which of these is an advantage of parallel circuits over series circuits?

A. If the battery dies, energy can still flow through the receivers.B. The current is stronger through the receivers.C. The voltage is stronger from the battery.D. If one receiver stops the energy flow, the other receivers can still work.

12. What will happen to the second light bulb if the first light bulb burns out?

A. Nothing will change.B. It will also go out.C. It will explode.D. It will get brighter.

13. In a closed electrical circuit, what visible evidence indicates that energy is flowing?

A. connected wiresB. a closed switchC. a new batteryD. a light bulb lighting up

14. The following diagram shows a wire with a magnetic field around it. Which of the following describes the direction of the current?

A. from A to BB. anticlockwiseC. from B to AD. clockwise

15. The following diagram shows two bar magnets. Which of the following describes the interaction between the two magnets?

A. The magnetic fields will cancel each other outB. The magnets will attract each other.C. There will be no interaction between the magnets.D. The magnets will repel each other.

16. The following diagram shows a permanent bar magnet. What would happen to the magnetic field if the bar magnet were cut in half

along the center line?

A. Both halves would have only south poles.B. Its magnetism would be destroyed.C. One half would be the south pole and the other half would be the north pole.D. Each half would have a north pole and a south pole.

17. The following diagram shows a magnetic field going into the page. A negatively charged particle enters the field in the direction shown in the diagram. How will the magnetic field affect the path of the charged particle?

A. The magnetic field will not change the path of the particle.B. The magnetic field will be canceled out by the charge of the particle.C. The magnetic field will repel the particle and it will not enter the field.D. The magnetic field will bend the path of the particle.

18. A metal detector works by creating a magnetic field. When an activated detector comes near a piece of metal, what most likely happens so that it is detected?

A. The metal becomes hot, and the detector senses the temperature change.B. The magnetic field creates a current in the piece of metal, and when the detector comes near the current it completes a circuit in the detector.C. The metal is magnetically attracted to the metal detector, and the metal detector pulls the metal toward itself.D. The metal interrupts or changes the field, and the detector senses the change.

19. Look at the electromagnet below. Which of the following materials would generate the strongest magnetic field if used as the

core?

A. siliconB. aluminumC. carbonD. iron

20. What is the relationship between electricity and magnetism?

A. A moving magnet creates a magnetic field, and an electric current makes electrons stand still.B. A moving magnet creates a current, and a still magnet creates a current.C. An electric current creates a magnetic field, and a moving magnet creates a current.D. An electric current creates a magnetic field, and electrons that are motionless create a magnetic field.

Reminders

• Make sure that you have written down your point code from the front board

• All pretests are due to be completed no later than Monday @9:30 am.

• If completed the grade will not count against your average.

• If incomplete you will receive a 0 major. • Make sure that you leave your science workbooks

on the shelf to be graded. • Make sure that you get your agenda signed before

leaving.