How can we calculate the filament resistance of a lamp rated at 120W and 120V?
The filament resistance of a lamp rated at 120W and 120V can be calculated using the formula R = V^2/P, where R is resistance in ohms, V is voltage in volts, and P is power in watts. Therefore, R = (120V)^2 / 120W = 120 ohms. Hence, the filament resistance of the lamp is 120 ohms.
Filament Resistance in Incandescent Light Bulbs
The filament resistance is a crucial aspect when it comes to incandescent light bulbs. These bulbs operate by passing an electric current through a thin wire filament, which heats up and emits light. The filament in an incandescent bulb is typically made of tungsten due to its high melting point and ability to withstand the high temperatures necessary for light emission.
Factors Affecting Filament Resistance
The resistance of the filament significantly influences the amount of current flowing through the bulb and the heat generated. Filament resistance is directly proportional to its length and inversely proportional to its cross-sectional area. Consequently, longer and thinner filaments have higher resistance compared to shorter and thicker filaments.
In conclusion, the filament resistance of a lamp rated at 120W and 120V is 120 ohms. Understanding the filament resistance is essential for determining the bulb's performance and efficiency.