The magnetic field produced by a bar magnet can be made visible using iron filings, which align to the magnetic field, as shown in the image above. How does the magnetic field in the image compare to Earth's magnetic field?

a. The bar magnet has two poles at W and Y, and the magnetic field produced by Earth also has two poles and looks similar to the bar magnet.

b. The bar magnet has two poles at W and Y, but the magnetic field produced by Earth has three poles and looks different from the bar magnet.

c. The bar magnet has three poles at W, X, and Y, and the magnetic field produced by Earth also has three poles and looks similar to the bar magnet.

d. The bar magnet has three poles at W, X, and Y, but the magnetic field produced by Earth has two poles and looks different from the bar magnet.

In the future, people will only enjoy one sport: electrodisc. in this sport, you gain points when you cause metallic discs hovering on a field to exchange charge. you are an electrodisc player playing the popular four disc variant. the disks have charges of qa = −8.0 µc, qb = −2.0 µc, qc = +5.0 µc, and qd = +12.0 µc. (1) you bring two disks together and then separate them. you measure the resulting charge of these two disks and find that it is +5.0 µc per disk. which two disks did you bring together? (a) a and b (b) a and c (c)a and d (d)b and c(e) b and d (f) c and d. (2) you bring three disks together and then separate them. you measure the resulting charge of these three disks and find that it is +3.0 µc per disk. which three disks did you bring together? a, b, and c (a) a, b, and d (c) a, c, and d (d) b, c, and d. (3) given the resulting charge of each disk measured in (b) is +3.0 µc, how many electrons would you need to add to a disk of this charge to electrically neutralize it? electrons