WRITTEN WORK NO. 4
1. Choose the letter of the best answer. 1. Which of these will electromagnet pick up? A. pencil
B.plastic
C. thumb tack
D. piece of wood
2. What kind of magnet is an electromagnet?
A. permanent
B.temporary
C. semi-permanent
D. none of the above
3. Which of these increases the strength of electromagnets?
A. Turning the current off. B. Increasing the number of loops.
C. Decreasing the number of loops of wire around the iron core.
D. Increasing the number of loops in the core and turning off the current.
4. Which does not affect the magnetism of an electromagnet?
A. magnet
C. number of coils
B. number of the batteries
D. size of the nail.
5. What material is produced when coil of wire is wind around an iron nail?
A. battery
C. electromagnet
B. circuit
D. magnet
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