Understanding how to calculate electric energy when given the voltage and charge is essential in various applications, from battery management to electrical engineering. The relationship between these quantities can be described using a straightforward formula.
The Formula: \( E = V \cdot Q \)
The formula to find electric energy using voltage and charge is:
\[ E = V \cdot Q \]
Where:
- \( E \) is the electric energy (measured in joules, J)
- \( V \) is the voltage (measured in volts, V)
- \( Q \) is the electric charge (measured in coulombs, C)
Example 1: Smartphone Battery
Question: A smartphone battery operates at a voltage of 4.2 volts and has a charge capacity of 3000 coulombs. What is the total electric energy stored in the battery?
Calculation:
Given:
- \( V = 4.2 \) V
- \( Q = 3000 \) C
Using the formula:
\[ E = V \cdot Q = 4.2 \cdot 3000 = 12600 \, \text{J} \]
Result: The total electric energy stored in the smartphone battery is 12600 joules.
Example 2: Electric Scooter Battery
Question: An electric scooter battery operates at a voltage of 48 volts and stores a charge of 5000 coulombs. What is the electric energy stored in the battery?
Calculation:
Given:
- \( V = 48 \) V
- \( Q = 5000 \) C
Using the formula:
\[ E = V \cdot Q = 48 \cdot 5000 = 240000 \, \text{J} \]
Result: The electric energy stored in the electric scooter battery is 240000 joules.
Example 3: Power Supply for a Device
Question: A power supply provides 12 volts to a device and delivers a charge of 250 coulombs. How much electric energy is supplied to the device?
Calculation:
Given:
- \( V = 12 \) V
- \( Q = 250 \) C
Using the formula:
\[ E = V \cdot Q = 12 \cdot 250 = 3000 \, \text{J} \]
Result: The electric energy supplied to the device is 3000 joules.
Conclusion
By using the formula \( E = V \cdot Q \), you can easily find the electric energy when the voltage and charge are known. This calculation is vital in various fields such as battery technology, electric vehicles, and electronic devices. Understanding how to calculate electric energy helps in designing efficient systems and managing energy resources effectively.
