Which of earth's compounds makes the planet unique because it can exist in solid, liquid, or gaseous states under normal conditions? a. water b. methane c. ammonia d. ozone

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.

area of focus