What is the voltage across a 10-ohm resistor if a current of 1 ampere flows through it?
The correct answer is B: 10 volts. The voltage across a 10-ohm resistor if a current of 1 ampere flows through it is 10 volts. Using Ohm's Law: E = I × R = 1 × 10 = 10 volts.
This is a straightforward application of Ohm's Law. When 1 ampere flows through a 10-ohm resistor, the voltage across it is 10 volts. This calculation is essential for understanding circuit behavior and verifying component operation. The formula E = I × R shows that voltage equals current times resistance, which is the fundamental relationship in DC circuits.
Exam Tip
Voltage = Current × Resistance. Remember: E = 1A × 10Ω = 10V. Multiply current by resistance to find voltage.
Memory Aid
"**E** = **1**A × **1**0Ω = **1**0V (think '1×10 = 10')"
Real-World Application
You're testing a power supply circuit. You measure 1 ampere flowing through a 10-ohm resistor. Using E = I × R, you calculate the voltage: E = 1 × 10 = 10 volts. This helps you verify the circuit operation and understand power dissipation (10 watts).
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. 1 volt would be using the current value as voltage, which doesn't follow Ohm's Law. Voltage must be calculated as current times resistance.
Option C: Incorrect. 11 volts would be adding current and resistance (1 + 10), which is mathematically invalid.
Option D: Incorrect. 9 volts would be subtracting current from resistance (10 - 1), which is mathematically invalid.
题目解析
The correct answer is B: 10 volts. The voltage across a 10-ohm resistor if a current of 1 ampere flows through it is 10 volts. Using Ohm's Law: E = I × R = 1 × 10 = 10 volts. This is a straightforward application of Ohm's Law. When 1 ampere flows through a 10-ohm resistor, the voltage across it is 10 volts. This calculation is essential for understanding circuit behavior and verifying component operation. The formula E = I × R shows that voltage equals current times resistance, which is the fundamental relationship in DC circuits.
考试技巧
Voltage = Current × Resistance. Remember: E = 1A × 10Ω = 10V. Multiply current by resistance to find voltage.
记忆口诀
**E** = **1**A × **1**0Ω = **1**0V (think '1×10 = 10')
实际应用示例
You're testing a power supply circuit. You measure 1 ampere flowing through a 10-ohm resistor. Using E = I × R, you calculate the voltage: E = 1 × 10 = 10 volts. This helps you verify the circuit operation and understand power dissipation (10 watts).
错误选项分析
Option A: Incorrect. 1 volt would be using the current value as voltage, which doesn't follow Ohm's Law. Voltage must be calculated as current times resistance. Option C: Incorrect. 11 volts would be adding current and resistance (1 + 10), which is mathematically invalid. Option D: Incorrect. 9 volts would be subtracting current from resistance (10 - 1), which is mathematically invalid.
知识点
Ohm's Law calculation, Voltage calculation, E = I × R, Resistor voltage
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.