Energy Transformations — Unit test Answers

The strength of a magnetic field around a wire carrying a current of 20 A is 0.004 T. What is the strength of the magnetic field if the current is changed to 40 A?

Barton conducts an experiment using three metallic bars that might be magnets. The bars are labeled A, B, and C. The ends of each bar are numbered 1 or 2.He places the end of one bar close to an end of a second bar and records his results in the table shown.Based on the data, which prediction should he expect to occur?

Pedro uses a bar magnet to pick up a nail. He then touches the tip of the nail to some staples.

A positive charge moving up enters a magnetic field pointing out of the screen. What is the direction of the magnetic force on the charge?