Precision is related to the uncertainly in a measurement: true or false

the electric field is a “force field” around a charged object that illustrates the direction the electric force would push an imaginary 

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.