Question

Heating effect of current is used in :

• A. electric generator
• B. bulb
• C. battery
• D. electric motor

Hint:

The heating effect of current (Joule heating) means that when current flows through a resistor, it gets hot. This effect is {used intentionally} in devices like:
Electric heaters, toasters, kettles, irons.
Incandescent light {bulbs} (filament gets so hot it glows).
Fuses (wire melts due to heat if current is too high). Generators, motors, and batteries are not primarily designed to produce heat as their useful output.

Answer 1

The Correct Option is B

Concept: The heating effect of electric current, also known as Joule heating or resistive heating, is the phenomenon where the passage of an electric current through a conductor produces heat. This effect is described by Joule's law, \(P = I^2R\), where \(P\) is power dissipated as heat, \(I\) is current, and \(R\) is resistance. Step 1: Understanding the application of the heating effect The heating effect of current is utilized in devices where the primary purpose is to generate heat or light (as a byproduct of intense heat). Step 2: Analyzing the options
(1) Electric generator: A generator converts mechanical energy into electrical energy. While some heat is produced due to internal resistance (an undesired energy loss), its primary function is not based on the heating effect.
(2) Bulb (Incandescent bulb): An incandescent light bulb works by passing current through a thin filament. The filament has high resistance, and due to the heating effect, it becomes extremely hot (incandescent) and emits light. This is a direct application of the heating effect. Other heating devices like electric heaters, toasters, electric irons also work on this principle.
(3) Battery: A battery is a source of electrical energy, converting chemical energy into electrical energy. Heat can be generated within a battery due to internal resistance, especially during high current draw or charging/discharging, but this is usually an undesirable side effect and not its primary purpose.
(4) Electric motor: An electric motor converts electrical energy into mechanical energy (motion). Similar to a generator, heat produced due to winding resistance is an energy loss and not the intended useful output. Step 3: Identifying the device that primarily uses the heating effect Among the given options, the bulb (specifically an incandescent bulb) is designed to utilize the heating effect of current to produce light. Many other common heating appliances also rely on this effect.