Electric current (\(I\)) can be calculated when you know the electric power (\(P\)) and the voltage (\(V\)). The relationship between power, current, and voltage is given by the formula:
\[ P = V \cdot I \]
To find the electric current, rearrange the formula to solve for \(I\):
\[ I = \dfrac{P}{V} \]
Where:
- \(P\) is the electric power (measured in watts, W)
- \(V\) is the voltage (measured in volts, V)
- \(I\) is the electric current (measured in amperes, A)
Example 1: Household Light Bulb
Question: A household light bulb consumes 60 watts of power when connected to a 120-volt supply. What is the electric current flowing through the light bulb?
Calculation:
Given:
- \(P = 60\) W
- \(V = 120\) V
Using the formula:
\[ I = \dfrac{P}{V} = \dfrac{60}{120} = 0.5 \, \text{A} \]
Result: The electric current flowing through the light bulb is 0.5 amperes.
Example 2: Electric Heater
Question: An electric heater uses 1500 watts of power when connected to a 240-volt supply. What is the electric current in the heater?
Calculation:
Given:
- \(P = 1500\) W
- \(V = 240\) V
Using the formula:
\[ I = \dfrac{P}{V} = \dfrac{1500}{240} \approx 6.25 \, \text{A} \]
Result: The electric current in the heater is approximately 6.25 amperes.
Example 3: Smartphone Charger
Question: A smartphone charger has a power output of 18 watts and operates at 9 volts. What is the electric current provided by the charger?
Calculation:
Given:
- \(P = 18\) W
- \(V = 9\) V
Using the formula:
\[ I = \dfrac{P}{V} = \dfrac{18}{9} = 2 \, \text{A} \]
Result: The electric current provided by the smartphone charger is 2 amperes.
By understanding how to calculate the electric current using the power and voltage, you can apply this knowledge to various real-life scenarios. This is crucial for designing and troubleshooting electrical and electronic systems, ensuring they operate safely and efficiently.
