II. Choose the letter of the correct answer

9. Which material can be a conductor for an electromagnet?

A. rubber B. copper C. plastic D. cotton

10. Which object is not used in making an electromagnet?

A. electricity B. wire C. magnet D. core

11. Which activity can be done with the use of an electromagnet?

A. keeping a room well – lighted C. Lifting the refrigerator

B. sweeping the floor D. Sewing a dress

12. How does an electromagnet work?

A. When an insulated wire is wrapped around an iron rod, the rod becomes magnetized

B. When electric current flows through the wire wrapped around an iron core

C. An electromagnet behaves like magnet only when the wire is wrapped around an iron core

D. An electromagnet maintains its magnetic properties even without the source of electricity

13. David wants to construct an electromagnet. Has a long piece of iron wire and two dry cells. What else does he

need?

A. iron screw B. plastic tube C. glass tube D. aluminum screw

14. You are going to construct an electromagnet, which of the following materials will you need.?

A. dry cell B. iron nail C. wire D. all of these

15. The following are all needed in constructing a simple electromagnet, which is NOT?

A. thread B. nail C. wire D. battery

16. In an electromagnet, which of the following serves as the conductor of electricity?

A. battery B. coil of wire C. core D. pins and needles

17. Which one of the following is NOT a part of an electromagnet?

A. the wire coil C. the dry cell as the source of electricity

B. the nail as the core D. pins, clips, and needles attracted by an electromagnet

18. What happens when a part of an electromagnet is disconnected?

A. It loses its magnetism.

B. Electricity continues to flow through it.

C. The electromagnet becomes a permanent magnet.

D. There is an increase in the number of materials attracted.

19. Which is TRUE about electromagnets?

A. They are permanent.

B. They don’t need a battery.

C. Increasing the battery makes the electromagnet weaker.

D. Increasing the number of coils makes the electromagnet stronger.

20. Manny wants to increase the strength of an electromagnet. What should Manny do?

A. Decrease the amount of electric current. C. Stop the flow of electricity.

B. Remove the iron core. D. Increase the turns of the wire.


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Need ko na po kasi​