Lamp Power Calculation
The power consumed by an electrical device is determined by the voltage across it and the current flowing through it.
The formula relating power (P), voltage (V), and current (I) is:
$ P = V \times I $Given values from the question:
- Voltage ($V$) = 450V
- Current ($I$) = 0.4A
Power Calculation Steps
Substitute the given values into the power formula:
$ P = 450\text{V} \times 0.4\text{A} $Perform the multiplication:
$ P = 180 \text{ Watts} $Therefore, the power of the lamp is 180W.
Important Questions from Power in Electric Circuits
Which one of the following terms cannot represent electrical power in a circuit?
An electric bulb is connected to 220 V generator. The current drawn is 600 mA. What is the power of the bulb?
- What is the current required to light a 60 W incandescent bulb in a domestic supply of 240 V ?
Which one of the following formulas does not represent electrical power?
In an electric circuit, a wire of resistance 10 Ω is used. If this wire is stretched to a length double of its original value, the current in the circuit would become :
