A technician is inspecting two identical ceramic heater plates, Plate A and Plate B, inside a vacuum deposition chamber.
Plate A is currently active and has reached a temperature of 180∘C180^{\circ}\text{C}180∘C.
Plate B is turned off and is at a room temperature of 15∘C15^{\circ}\text{C}15∘C.
Identify which plate emits electromagnetic radiation at a higher rate and explain your reasoning.
Explain why, under normal ambient room lighting, both plates appear identical to the technician's eyes, and identify the primary region of the electromagnetic spectrum in which these plates are emitting.