Read the questions carefully.Write the letter of the correct answer.

7. To increase the strength of
an electromagnet
A. increase the current in the coil.
B. add an iron center in the coil.
C. increase the number of loops in the wire.
D. all of the above
8. The following are the factors that affect the strength of an electromagnet except
A. Number of coils around the core
B. Number of dry cell used
C. Number of bulbs used
D. Size of the iron core

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