If a pitch from a moving vehicle sounds lower to a hearer, where is the vehicle in relation to the hearer? past the hearer before the hearer above the level of the hearer’s ear below the level of the hearer’s ear

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.

see earlier answer