Investigators should collect virtually everything from a crime scene. true or false?

false

Explanation:

its a trick question. not all evidence should be collected from the crime scene due to not all the evidence be useful.

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.

v=ir = 3x15 =45 v