Determining the electric power using voltage and current is essential for understanding the energy consumption of electrical devices. The relationship between these quantities is expressed through a specific formula, which we will explore with practical examples.
The Formula: \( P = V \cdot I \)
Where:
- \( P \) is the electric power (measured in watts, W)
- \( V \) is the voltage (measured in volts, V)
- \( I \) is the current (measured in amperes, A)
Example 1: Power Consumption of a Laptop Charger
Question: A laptop charger operates at a voltage of 20 volts and a current of 3 amperes. What is the power consumption of the laptop charger?
Calculation:
Given:
- \( V = 20 \) V
- \( I = 3 \) A
Using the formula:
\[ P = V \cdot I = 20 \cdot 3 = 60 \, \text{W} \]
Result: The power consumption of the laptop charger is 60 watts.
Example 2: Power Output of a Solar Panel
Question: A solar panel generates a voltage of 18 volts and a current of 5 amperes. What is the power output of the solar panel?
Calculation:
Given:
- \( V = 18 \) V
- \( I = 5 \) A
Using the formula:
\[ P = V \cdot I = 18 \cdot 5 = 90 \, \text{W} \]
Result: The power output of the solar panel is 90 watts.
Example 3: Power Consumption of an Electric Heater
Question: An electric heater operates at a voltage of 240 volts and a current of 10 amperes. What is the power consumption of the electric heater?
Calculation:
Given:
- \( V = 240 \) V
- \( I = 10 \) A
Using the formula:
\[ P = V \cdot I = 240 \cdot 10 = 2400 \, \text{W} \]
Result: The power consumption of the electric heater is 2400 watts.
