Complete question is;
Selena drew a diagram to show how current moves in a loop of wire that is placed between two magnets. At top left a piece of magnet labeled N and at top right a piece labeled S. Between these a square coil of wire with green arrows at its ends away from the magnets pointing away from the magnets. Red arrows point from N to S. Which best explains how Selena can correct her error?
A) She can change the magnets so like poles are facing each other.
B) She can change the arrows so they show current traveling in opposite directions on the sides of the loop.
C) She can change the arrows so they show the magnetic field reversing direction between the magnets.
D) She can change the magnetic poles so they are both on one side of the loop.
Answer:
B) She can change the arrows so they show current traveling in opposite directions on the sides of the loop.
Explanation:
Since the direction of the arrows point north and south whereas the magnets are east and west, it means the arrows are not pointing in the correct direction. To correct it she will have to make sure the arrows are pointing in opposite directions of the magnet via the sides of the loop.
C. Wavelength is the length of one complete wave cycle 
Wavelength of a sine wave, λ, can be measured between any two points with the same phase, such as between crests, or troughs, or corresponding zero crossings as shown
Answer:
The force will be attractive.
Explanation:
Since we the sum of the charges is 0 they must have opposite charges and equal magnitudes.
And Opposite charges are attaractive towards each other.
Answer: B, C, A
Explanation:
Electrostatic force F = kq²/d²
Let the force on A be Fa, and B be Fb and C be Fc.
For Fa, distance between A and B is d, and distance between A and C is 2d
For Fb, distance between B and A is d, and distance between B and C is d
For Fc, distance between C and B is d, and distance between C and A is 2d
Also, the charge of each charge affects the sign of the force.
Check the attachment below
