Why does the filament of a light bulb glow but the connecting wires do not?

Why does the filament of a light bulb glow but the connecting wires do not?

Answer: Two wires do not emit light even though the same current flows in the two thick wires connecting the filaments in the electric lamp. Thick wires connecting the filaments have shorter lengths and relatively larger cross-sections. So their resistance is less. As a result, both of them do not heat up so much that they do not emit light, despite running the same current.