Ive tried multiple answers but cant get it right.

Which of the following changes would induce an electromotive force (emf) in the loop? When you consider each option, assume that no other changes occur.

a. The magnitude of B_vec increases.
b. The magnitude of B_vec decreases.
c. The loop rotates about the vertical axis (vertical dotted line) shown in the diagram.
d. The loop rotates about the horizontal axis (horizontal dotted line) shown in the diagram.
e. The loop moves to the right while remaining in the plane of the page.
f. The loop moves toward you, out of the page, while remaining parallel to itself.

can be multiple options.

without a diagram, I cant tell what the rotations c, d, e, f do. What is needed is a loop containing a changing B field. Rotating a loop in a field does that (the amount of B*Area changes), or varying B, or moving a wire perpendicular to a field.

Wires, or loops, moving in the direction of B wont induce an EMF>

the image is a square loop on the xy plane with the B field directed into the page. that should help. Im pretty sure moving it right wont do anything because same number of field lines passing. Im not sure if changing the magnitude does anything.

moving it to the right wont change. Wont changing the B magnitude change the amount of flux (B*Area) in the loop?

EMF= d/dt (B*Area)

thats what i thought. so i thought it would be abc. but then wouldnt moving it in the direction of the b field cause more lines to pass in less time?

Ive tried abcdf, abcf,abc,c, none of those work.

I have no idea what the direction of b is, unless you mean B, the magnetic field. In that case, no magnetic flux is changing. IF B is into the page, then f cannot be right.

To determine which of the given options would induce an electromotive force (emf) in the loop, we need to understand Faraday's law of electromagnetic induction. According to this law, an emf is induced in a loop of wire when there is a change in magnetic flux passing through the loop.

Now, let's analyze each option and determine if it would induce an emf:

a. The magnitude of B_vec increases:
When the magnitude of the magnetic field (B_vec) passing through the loop increases, there is a change in magnetic flux. According to Faraday's law, this change in flux will induce an emf in the loop. Therefore, option a is correct.

b. The magnitude of B_vec decreases:
Similarly, when the magnitude of the magnetic field passing through the loop decreases, there is a change in magnetic flux, which will induce an emf. Therefore, option b is also correct.

c. The loop rotates about the vertical axis (vertical dotted line) shown in the diagram:
Rotating the loop about the vertical axis will not change the magnetic flux passing through the loop. Therefore, option c does not induce an emf.

d. The loop rotates about the horizontal axis (horizontal dotted line) shown in the diagram:
Similar to option c, rotating the loop about the horizontal axis will not change the magnetic flux passing through the loop. Therefore, option d does not induce an emf.

e. The loop moves to the right while remaining in the plane of the page:
If the loop moves to the right while staying in the plane of the page, there will be no change in the magnetic flux passing through the loop. Therefore, option e does not induce an emf.

f. The loop moves toward you, out of the page, while remaining parallel to itself:
When the loop moves toward you, out of the page while remaining parallel to itself, the magnetic flux passing through the loop changes. This change in flux will induce an emf according to Faraday's law. Therefore, option f is correct.

Based on the analysis above, options a, b, and f would induce an electromotive force (emf) in the loop.