Question

(multi - select question)
how are the electromagnets in a mri machine similar to all other electromagnets, and how could a doctor increase a mri machines magnetic field (select two choices)
□ a dont select
□ b they have coils of wire wrapped around iron cores connected to electrical current.
□ c mri machines consist of many permanent magnets that cannot be turned off.
□ d to increase the magnetic field of an mri machine, increase the electrical current.

1. standard 02: non - contact forces can be either attractive or repulsive.

a student was asked to demonstrate that fields exist between objects exerting forces on each other even though the objects are not in contact. the results of this demonstration are shown above.
(multi - select question) select two pictures that show repulsion, and determine which kind of non - contact force these pictures are displaying. (select two choices)
□ a picture 04 shows electrostatic repulsion.
□ b picture 01 is demonstrating magnetic attraction.
□ c pictures 03 is demonstrating magnetic repulsion.
□ d dont select
□ e pictures 02 is demonstrating magnetic repulsion.

Explanation:

1. For the MRI - related question: Electromagnets in MRI machines have coils of wire wrapped around iron cores connected to electrical current (similar to other electromagnets), and increasing the electrical current increases the magnetic field.
2. For the non - contact force question: Magnetic repulsion occurs when like poles of magnets face each other. Picture 03 shows two magnets with like poles facing, demonstrating magnetic repulsion. Picture 04 shows two objects that seem to be charged particles repelling each other, which is electrostatic repulsion.

Answer:

For the MRI question: b. They have coils of wire wrapped around iron cores connected to electrical current; d. To increase the magnetic field of an MRI machine, increase the electrical current.
For the non - contact force question: a. Picture 04 shows electrostatic repulsion; c. Picture 03 is demonstrating magnetic repulsion.