Read each statement carefully. Choose the letter of the correct answer.

1. Which object is not used in making an electromagnet? *

A. electricity

B. wire

C. magnet

D. core

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

A. keeping a room well – lighted

B. Lifting the refrigerator

C. sweeping the floor

D. Sewing a dress

3. 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.

4. Why is the wire used in an electromagnet coiled? *

A. It has more force

B. It controls the field of attraction

C. It controls the flow of electricity

D. It controls the flow of electrons

5. Which of the following can make an electromagnet stronger? *

A. Adding more dry cells

B. Using a core with a bigger diameter

C. Increasing the number of turns in the coil of wire

D. All of the above

6. David wants to construct an electromagnet. He has a long piece of iron wire and two dry cells. What else does he need? *

A. iron screw

B. glass tube

C. plastic tube

D. aluminum screw

7. Which of the following devices makes use of electromagnet? *

A. Electric bell

B. telephone

C. Electric buzzer

D. all of the given options

8. Which one of the following is not a part of an electromagnet? *

A. The wire coil

B. The nail as the core

C. The dry cell as the source of electricity

D. Pins, clips, and needles attracted by the electromagnet

9. 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.

10. You notice that a part of the cord attached to your electric iron is worn out. Which of the following can you do as a safety precaution ? *

A. Wrap the wornout part of the cord with electric tape.

B. Wrap the wornout part of the cord with a piece of paper.

C. Wrap the wornout part of the cord with a piece of rag

D. Wrap the wornout part of the cord with a piece of tin foil

11. Which is an example of a temporary magnet? *

A. bar magnet

B. horseshoe magnet

C. electromagnet

D. magnetite

12. Which can increase the strength of an electromagnet?

A. increasing the number of coils around the nail

B. Increasing the number of batteries or coils around the nail

C. decreasing the number of wires around the nail

D. Decreasing the number of coils around the nail

13. The following statements are not true about electromagnet, EXCEPT one. *

A. The smaller the size of the battery, the stronger is the electromagnet is.

B. The bigger the size of the soft-iron core is, the weaker the electromagnet is.

C. The greater the number of batteries, the weaker the electromagnet is.

D. The greater the number of batteries, the stronger the electromagnet is.

14. 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.

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

A. Decrease the amount of electric current.

B. Remove the iron core.

C. Stop the flow of electricity.

D. Increase the turns of the wire.

pls po need po po to ngayon​