Question

¿Cuál es la potencia de una lámpara de incandescencia que se conecta a la red de 220 V, sabiendo que tiene una resistencia de 50 ohmios?

Answer 1

Answer:

• 1,000W (rounded to one significant figure)

Explanation:

I will answer in English.

The question is:

• What is the power of a filament lamp that connects to the 220 V network, knowing that it has a resistance of 50 ohms?

Solution

Power, voltage, resistance, and current, are related by either of the following equations:

• P = V × I

• P = R × I²

• P = V² / R

Where:

• P is power in watts (W)

• R is resistance in ohms (Ω)

• V is voltage in volts (V), and

• I is current in amperes (A)

Since you know the voltage (220V) and the resistance (50Ω), you can use the last equation:

• P = V² / R

• P = (220v)² / (50Ω)

• P = 968 W

Since the magnitude 50Ω has one significant figure, your answer should be rounded to one significant figure. That is 1,000W.