Law stating that "force is directly proportional to product of charges and inversely proportional to square of separation between them" is called

Options

A. Newton’s law.
B. Coulomb’s law
C. Gauss’s law.
D. Ohm’s law

Explanation

To solve the question, we need to identify the law that describes the relationship between the force acting between two charges, their magnitudes, and the distance separating them. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Relationship
The question states that the force (F) between two charges (q1 and q2) is directly proportional to the product of the charges and inversely proportional to the square of the distance (r) between them. This can be expressed mathematically as:
\[ F \propto \frac{q_1 \cdot q_2}{r^2} \]

### Step 2: Introduce a Constant of Proportionality
To convert the proportionality into an equation, we introduce a constant (k), which leads to:
\[ F = k \frac{q_1 \cdot q_2}{r^2} \]

### Step 3: Identify the Constant
The constant \( k \) in this context is known as Coulomb's constant. It is a proportionality constant that quantifies the amount of force between two unit charges separated by a unit distance in a vacuum.

### Step 4: Recognize the Law
This relationship is known as **Coulomb's Law**, which describes the electrostatic force between charged objects.

### Final Answer
Thus, the law stating that "force is directly proportional to the product of charges and inversely proportional to the square of separation between them" is called **Coulomb's Law**.

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