1) What is the advantage of an electromagnet compared to magnet?
A. Electromagnet is lighter
B. Electromagnet can be turned on and off
C. Permanent magnet cannot be used to pick up metals
D. Electromagnet can be used for attracting more metals

2)What are the factors that affect the strength of an electromagnet
A. Battery, magnet and core
B. Dry cells, nail and magnet
C. Number of coil/wire, number of batteries/dry cell, and properties of the core

3)What could make an electromagnet stronger?
A. Use a weaker battery
B. Reverse the poles of the magnet
C. Remove all the coils and the nail
D. Add more coils and the nails

4)Complete this sentence "In order to form an electromagnet, a/an ____ current should flow through a coil of ____ covered arround a/an ____."
A. Electric, wire, iron
B. Iron, wire, electric
C. Iron, electric, wire
D. Wire, iron, electric

5)You conducted an experiment using a very strong electromagnet. How can you make it weaker?
A. Add more loops
B. Use a thicker wire
C. Add more batteries
D. Wrap the wire loosely

Please say the answers dont answer random just for points because my points will be a waste thank you :(​