What must be the magnitude of the rate of change of the current in order for the self-induced emf to equal 6.30 mV

Answertraveling around a circular trackexplanation"traveling around a circular track" is the best answer as you could be traveling around a circular track at a constant speed. your velocity would therefore have the same magnitude but will always be constantly direction. since acceleration is the rate of change of velocity, the rate of change will only involve the direction of velocity and not the magnitude.wrong choices: "an object at rest" does not accelerate at all"increasing speed while traveling around a curve" means that the acceleration will not be constant due to only change in direction; it will be constant due to both magnitude and direction"an object in free fall" does not necessarily change direction 

Amicroscope, because these cells are so small that you would not be able to see them, or what they attack without it.

Following the american gauge wire standards ,the larger gauge number, the slimmer the wire and thus the smaller current carrying capacity it can have.then both statements would be incorrect, as they are saying the opposite of what it is actually is.(smaller gauge numbers have thicker wires and can carry more current)