Question

Question 4 (3 points)
Albin tests how the number of dry cell batteries affects the strength of an electromagnet. What variables must he keep the same in his experiment? Select all that apply.

a
the number of paper clips attracted to the electromagnet
b
the width of the iron nail
c
the kind of paper clips used in each trial
d
the number of wire turns around the iron nail
e
the number of dry cell batteries
f
the strength of the magnetic field
Question 5 (1 point)
Greg built a simple electromagnet with copper wire, an iron bolt, and a 1.5-volt battery. The electromagnet was able to lift a paper clip from 3 centimeters away. Which of the following is NOT a way Greg can improve the strength of his electromagnet?

a
He can reverse the orientation of the battery.
b
He can replace the 1.5-volt battery with a battery of higher voltage.
c
He can use a longer piece of wire that wraps more times around the bolt.
d
He can use a thicker piece of copper wire.
Question 6 (1 point)
Read the passage about Brian.

Brian made an electromagnet in his science class. He spread out several paper clips, all made of the same material and the same size, on a lab table. Holding his electromagnet in a fixed spot, he tried to attract as many paper clips as possible. He observed that there were two paper clips that were not attracted to his electromagnet.

What is the most likely conclusion Brian can draw about his observation?

a
The two paper clips were not light enough to be pulled by the magnet.
b
The two paper clips were outside the magnet's electromagnetic field.
c
The two paper clips were repelled by the electromagnet and not picked up.
d
The two paper clips did not have magnetic properties like the others.
Question 7 (1 point)
A student creates an electromagnet and holds it near two paper clips.



Paper clip Y is not attracted to the magnet. Which step should the student take to attract it?

a
The student should wrap the coil fewer times around the nail.
b
The student should use a smaller core in the magnet.
c
The student should use a battery with less energy.
d
The student should move the magnet closer to the paper clip.

Answer 1

Question 4: b, c, d
- Keep the nail width, kind of paper clips, and number of wire turns the same so only the number of batteries changes.

Question 5: a
- Reversing the battery only reverses polarity, it doesn’t increase the magnet’s strength.

Question 6: d
- The two paper clips likely did not have magnetic properties like the others.

Question 7: d
- Moving the magnet closer increases the magnetic field strength at the paper clip so it will be attracted.