Heating effect of electric current.
Explanation
The phenomenon in transformation of electrical energy into heat and light energy. When an electric current flows through a conductor with finite resistance, energy is dissipated in the form of heat. This is known as the heating effect of electric current or Joule heating.
Option Analysis
- Magnetic effect of electric current. is Incorrect: The magnetic effect of electric current refers to the production of a magnetic field around a current-carrying conductor. This principle is utilized in electromagnets, electric bells, and motors, not in the glowing of a bulb filament.
- Chemical effect of electric current. is Incorrect: The chemical effect of electric current involves chemical reactions occurring in a conducting solution (electrolyte) when current passes through it. Applications include electroplating and electrolysis.
- Heating effect of electric current. is Correct: In an incandescent bulb, the filament is made of a material with a high melting point and high resistance (typically Tungsten). As current passes through the filament, the heating effect causes its temperature to rise significantly (often above 2500°C), causing it to emit visible light (incandescence).
- Piezoelectric effect. is Incorrect: The piezoelectric effect describes the generation of an electric charge in response to applied mechanical stress in certain solid materials, or the reverse. It is not involved in the operation of a standard incandescent bulb.
Key Takeaway: The operation of an incandescent light bulb is a primary application of the heating effect of electric current (Joule’s Law of Heating), where high resistance in the filament converts electrical energy into heat and subsequently light.