4. Which device is used to supply electric power during brownouts? A. electric magnet C. generator B. magnetic wire D. motor
5. Electromagnets work when A. electric current passes through the coil. B. electric current passes through the core. C. ends of coil are disconnected from the electricity source. D. ends of coil are disconnected in one terminal of a dry cell.
6. What does an electromagnet produce? A. electric C. magnet B. magnetic D. magnetic field
7. 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.​