Explain constant and changing velocity.

To summarize, an object moving in a uniform circular motion is moving around the perimeter of the circle with a constant speed. While the speed of the object is constant, its velocity is changing. Velocity, being a vector, has a constant magnitude but a changing direction.

In order for the velocity to be constant, the magnitude of the velocity (or speed) and the direction of the velocity must not change. Therefore, an object that travels with constant velocity covers the same distance during each time interval and moves in the same direction during the same time interval.

Explanation:

Credit to the person who wrote the comment on your problem, i wrote it here so it is easier seen

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.