What is the current through a 24-ohm resistor connected across 240 volts?
The correct answer is C: 10 amperes. The current through a 24-ohm resistor connected across 240 volts is 10 amperes. Using Ohm's Law: I = E / R = 240 / 24 = 10 amperes.
This calculation demonstrates Ohm's Law for finding current. When a 24-ohm resistor is connected across 240 volts, the current is 10 amperes. This is essential for understanding circuit behavior and calculating power (P = E × I = 240 × 10 = 2400 watts). The formula shows that current increases with voltage and decreases with resistance.
Exam Tip
Current = Voltage / Resistance. Remember: I = 240V / 24Ω = 10A. Divide voltage by resistance to find current.
Memory Aid
"**I** = **2**40V / **2**4Ω = **1**0A (think '240/24 = 10')"
Real-World Application
You're testing a high-power amplifier. You connect a 24-ohm load across 240 volts. Using I = E / R, you calculate the current: I = 240 / 24 = 10 amperes. This helps you verify the load and calculate power (2400 watts).
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. 24,000 amperes would be multiplying voltage and resistance (240 × 24), which is mathematically incorrect. Current is voltage divided by resistance.
Option B: Incorrect. 0.1 amperes would be dividing resistance by voltage (24 / 240), which is the inverse of the correct formula.
Option D: Incorrect. 216 amperes would be subtracting resistance from voltage (240 - 24), which is mathematically invalid.
题目解析
The correct answer is C: 10 amperes. The current through a 24-ohm resistor connected across 240 volts is 10 amperes. Using Ohm's Law: I = E / R = 240 / 24 = 10 amperes. This calculation demonstrates Ohm's Law for finding current. When a 24-ohm resistor is connected across 240 volts, the current is 10 amperes. This is essential for understanding circuit behavior and calculating power (P = E × I = 240 × 10 = 2400 watts). The formula shows that current increases with voltage and decreases with resistance.
考试技巧
Current = Voltage / Resistance. Remember: I = 240V / 24Ω = 10A. Divide voltage by resistance to find current.
记忆口诀
**I** = **2**40V / **2**4Ω = **1**0A (think '240/24 = 10')
实际应用示例
You're testing a high-power amplifier. You connect a 24-ohm load across 240 volts. Using I = E / R, you calculate the current: I = 240 / 24 = 10 amperes. This helps you verify the load and calculate power (2400 watts).
错误选项分析
Option A: Incorrect. 24,000 amperes would be multiplying voltage and resistance (240 × 24), which is mathematically incorrect. Current is voltage divided by resistance. Option B: Incorrect. 0.1 amperes would be dividing resistance by voltage (24 / 240), which is the inverse of the correct formula. Option D: Incorrect. 216 amperes would be subtracting resistance from voltage (240 - 24), which is mathematically invalid.
知识点
Ohm's Law calculation, Current calculation, I = E / R, Resistor current
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.