1. Which of the following can make an electromagnetic stronger? A. Increase the number coils of the wire B. Add more dry cell C. Use a bigger core D. All of the above 2. Which device makes use of electromagnet? A. telephone B. electric buzzer C. electric bell D. all of the above 3. Which is a part of an electromagnet? A. wire B. pin C. thumbtacks D. needles 4. Which of the following is a conductor in an electromagnet? D. wood A. Copper B. rubber C. plastic 5. Which is NOT part of an electromagnet? A. magnet B. wire C. nail D. batterykavusk​