According to Ohm's law, which combination of units is the same as the unit for resistance?
A. volt \div ampere
B. ampere \times volt
C. volt + ampere
D. ampere \div volt
Answer (2)
Ohm's Law states that Voltage (V) equals Current (I) times Resistance (R): V = I × R .
Rearrange the formula to solve for Resistance (R): R = I V .
Express the units: Resistance (Ohm) = Voltage (Volt) / Current (Ampere).
The combination of units that represents resistance is volt ÷ ampere: volt ÷ ampere .
Explanation
Understanding Ohm's Law Ohm's law states the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit. The law is expressed as:
Ohm's Law Formula V = I × R
Solving for Resistance To find the unit for resistance, we need to rearrange the formula to solve for R:
Resistance Formula R = I V
Units of Resistance In terms of units, this means:
Resistance Units Resistance (in Ohms) = Voltage (in Volts) / Current (in Amperes)
Conclusion Therefore, the unit for resistance is volt ÷ ampere.
Examples
Ohm's law is fundamental in electrical engineering. For example, if you have a 12-volt power supply and you want to limit the current through an LED to 20 milliamperes (0.02 amperes), you can use Ohm's law to calculate the necessary resistance. Using R = V / I , the resistance would be R = 12 V /0.02 A = 600 Ohms. This calculation helps in designing circuits that protect components from excessive current.
According to Ohm's Law, the unit for resistance is represented as volts divided by amperes. Therefore, the correct answer is option A: volt ÷ ampere. This relationship is fundamental in understanding electrical circuits.
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