7 Question
Question 78.33 pts
How can the materials in the diagram be used to make a magnet?
Group of answer choices

A add more loops of wire to the iron nail

B replace the iron nail with a wood rod

C touch the ends of the wire to the ends of the battery

D place the nail closer to the iron filings

8 Question
Question 88.33 pts
Markeisha needs to create an electromagnet for her science project. She needs to create a magnet that can pick up iron filings out of a mixture of substances. Which list of materials would best help Markeisha build her electromagnet?
Group of answer choices

A glass rod, wire, battery

B battery, metal nail, wire

C glass rod, string, battery

D string, battery, metal nail

9 Question
Question 98.34 pts
Another student made an electromagnet with an iron nail with eight coils of wire wound around it connected to a 2-V battery. She wants to increase the strength of the electromagnet. What changes can she make to her design to increase its strength? Select all that apply.
Group of answer choices

A use a longer wire

B use a 4-V battery

C use two 1-V batteries instead of a 2-V battery

D wrap more coils of wire around the nail

10 Question
Question 108.34 pts
How is an electromagnet different from a bar magnet?
Group of answer choices

A A bar magnet is a temporary and is only magnetic when a current flows through a wire wrapped around the core.

B Only an electromagnet attracts materials made of iron.

C An electromagnet is temporary and is magnetic when a current flows through a wire wrapped around the core.

D Only a bar magnet has a real magnetic field.

11 Question
Question 118.34 pts
Students hypothesized that by running an electric current through the wire of the apparatus shown here, they could cause a non-magnetic nail to exhibit magnetic properties. What would be a reasonable way to test this?

(Also at bottom)

Group of answer choices

A Weigh the nail first before turning on the current and again while the current is on.

B Put the nail in water before turning the current on and again after turning the current off.

C Examine the nail under a microscope before turning the current on and again after turning the current off.

D See if iron filings will stick to the nail before turning the current on and again while the current was on.

12 Question
Question 128.34 pts
Joey and McKaleb build an electromagnet by wrapping a wire around a nail and connecting the wire to both terminals of a battery. When they connect the battery, they discover that the electromagnet can pick up 5 paperclips. They want to be able to pick up 8 paperclips. Joey and McKaleb brainstorm and think of 4 ways to modify their experiment so the electromagnet will pick up 8 paperclips. Which of these do you think they should try?

Add another battery.
Increase the number of times the wire is wrapped around the nail.
Reverse the wire so that the side touching the positive end of the battery is now touching the negative end.
Spread out the wire loops on the nail so they do not touch.
Group of answer choices

A All of these will increase the strength of the magnet since the strength of the magnet can be increased by changing the wire loops or the battery.

B Number 1, 2 and 4 will increase the strength of the magnet, but reversing the battery will make the magnet repel the paperclips.

C None of these will work. The boys should add a real magnet in addition to the electromagnet if they want to pick up more paperclips.

D Number 1 and 2 will increase the magnetic force, but number 3 and 4 will not increase the strength of the magnet.