I.Write the letter of the correct answer on the space provided.
_____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