16. An electromagnet can be made stronger by using
A. only one cell or battery
C. more pins
B. more cells or batteries
D. electricity
17. When you use 2 or more batteries, then there is alan
in its current
A. magnetic field B. no change
C. increase
D. decrease
18. This is a temporary magnet that may be produced by making electricity flow through a wire coiled
around an iron nail.
A. electromagnet B. magnetism C. electricity
D. dry cells
19. Nails can be tumed into magnet by
A. coiling a wire around it and letting the electricity flow into it
B. coiling a wire around the dry cells or batteries.
C. coiling dry cells or batteries in the wire
D. letting the electricity pass through it
20. How can you increase the strength of an electromagnet?
A. by letting the electricity pass through it C. by adding the more magnets
B. by adding more dry cells or batteries D. by adding longer wires​