Electric current (\(I\)) is the flow of electric charge (\(Q\)) through a conductor over a given period of time (\(t\)). The relationship between charge, current, and time is defined by the formula:
\[ Q = I \cdot t \]
To find the electric current, we can rearrange the formula to solve for \(I\):
\[ I = \dfrac{Q}{t} \]
Where:
- \(Q\) is the electric charge (measured in coulombs, C)
- \(I\) is the electric current (measured in amperes, A)
- \(t\) is the time (measured in seconds, s)
Example 1: Charging a Smartphone
Question: A smartphone battery receives a charge of 5400 coulombs over a period of 1.5 hours. What is the electric current supplied to the battery?
Calculation:
Given:
- \(Q = 5400\) C
- \(t = 1.5 \) hours = \(1.5 \times 3600 = 5400\) s
Using the formula:
\[ I = \dfrac{Q}{t} = \dfrac{5400}{5400} = 1 \, \text{A} \]
Result: The electric current supplied to the smartphone battery is 1 ampere.
Example 2: Electric Car Charging
Question: An electric car is charged with 864,000 coulombs of charge over a period of 8 hours. What is the electric current during the charging process?
Calculation:
Given:
- \(Q = 864,000\) C
- \(t = 8\) hours = \(8 \times 3600 = 28,800\) s
Using the formula:
\[ I = \dfrac{Q}{t} = \dfrac{864,000}{28,800} = 30 \, \text{A} \]
Result: The electric current during the charging process is 30 amperes.
Example 3: Flashlight Battery Usage
Question: A flashlight uses a charge of 1800 coulombs over a period of 2 hours. What is the electric current through the flashlight?
Calculation:
Given:
- \(Q = 1800\) C
- \(t = 2\) hours = \(2 \times 3600 = 7200\) s
Using the formula:
\[ I = \dfrac{Q}{t} = \dfrac{1800}{7200} = 0.25 \, \text{A} \]
Result: The electric current through the flashlight is 0.25 amperes.
By understanding the relationship between charge, current, and time, you can easily calculate the electric current in various real-life scenarios. This knowledge is essential for designing and troubleshooting electrical and electronic systems.
