The diagram shows the set-up for an electric doorbell. At bottom, a doorbell. Starting from midright, a wire attached to a contact screw runs to a power source and then to a bell and then to coil around both arms of a U shaped iron core. The coils plus core is labeled electromagnet with the lower arm of the core labeled N and the upper arm labeled S. The wire emerges from the coils to attach to a steel bar at its top end. The bottom end of the steel bar has a short piece of wire leading to a striker. Which best explains why the bell would not ring in this set-up? The circuit is open. The electromagnet has an iron core. The circuit is closed. The electromagnet is made of steel.

the answer is that the circuit is open,

Explanation:

if you look towards the switch its off, or open meaning no current can flow

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.

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.