Question

In an electric circuit, current is directly proportional to electromotive force and inversely proportional to the resistance. This is known as

• A. Darcy's Law
• B. Ohm's Law
• C. Faraday's Law
• D. Maxwell's Law

Hint:

A useful mnemonic for Ohm's Law is the "Ohm's Law Triangle". Draw a triangle, divide it in half horizontally, and then divide the bottom half vertically. Place V in the top section, and I and R in the bottom two sections. To find any variable, cover it up and see the relationship between the other two. (Cover V, you see I x R. Cover I, you see V R).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The question describes a fundamental relationship between current, voltage (electromotive force), and resistance in an electrical circuit. We need to identify the name of the law that defines this relationship.

Step 2: Detailed Explanation:
Let's analyze the description provided:
"Current is directly proportional to electromotive force (Voltage)" can be written as \( I \propto V \).
"Current is inversely proportional to the resistance" can be written as \( I \propto \frac{1}{R} \).
Combining these two proportionalities, we get:
\[ I \propto \frac{V}{R} \] This relationship is known as Ohm's Law, which is commonly written as:
\[ V = I \times R \] where:
V = Voltage (or electromotive force) in Volts
I = Current in Amperes
R = Resistance in Ohms
Let's look at the other laws mentioned:

• Darcy's Law: This law describes the flow of a fluid through a porous medium. It's used in hydrology and soil science, not electronics.

• Faraday's Law of Induction: This law relates a changing magnetic field to the induced electromotive force (voltage). It's the principle behind transformers and generators.

• Maxwell's Laws (Equations): These are a set of four fundamental equations that form the foundation of classical electromagnetism, optics, and electric circuits. Ohm's law can be derived from Maxwell's equations, but the specific statement in the question is Ohm's law itself.

Step 3: Final Answer:
The statement describes Ohm's Law.