Determining the current when the power and voltage are known is essential in various electrical applications. The relationship between these quantities can be easily calculated using a simple formula.
The Formula: \( P = V \cdot I \)
To find the current, we rearrange the formula as follows:
\[ I = \dfrac{P}{V} \]
Where:
- \( P \) is the power (measured in watts, W)
- \( V \) is the voltage (measured in volts, V)
- \( I \) is the current (measured in amperes, A)
Example 1: Current for a Refrigerator
Question: A refrigerator uses 240 watts of power and operates on 120 volts. What is the current drawn by the refrigerator?
Calculation:
Given:
- \( P = 240 \) W
- \( V = 120 \) V
Using the formula:
\[ I = \dfrac{P}{V} = \dfrac{240}{120} = 2 \, \text{A} \]
Result: The current drawn by the refrigerator is 2 amperes.
Example 2: Current for an Air Conditioner
Question: An air conditioner consumes 1800 watts of power and runs on 240 volts. What is the current?
Calculation:
Given:
- \( P = 1800 \) W
- \( V = 240 \) V
Using the formula:
\[ I = \dfrac{P}{V} = \dfrac{1800}{240} = 7.5 \, \text{A} \]
Result: The current for the air conditioner is 7.5 amperes.
Example 3: Current for a Television
Question: A television set uses 90 watts of power and operates at 110 volts. What is the current drawn by the TV?
Calculation:
Given:
- \( P = 90 \) W
- \( V = 110 \) V
Using the formula:
\[ I = \dfrac{P}{V} = \dfrac{90}{110} \approx 0.82 \, \text{A} \]
Result: The current drawn by the television is approximately 0.82 amperes.
