The equation` rarr sum e = sum IR` is applicable to which law ?

Options

A. Kirchhoff's third law
B. Kirchhoff's junction rule
C. Kirchhoff's second law
D. Newton's law

Answer

To determine which law the equation \( \sum E = \sum IR \) is applicable to, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Equation**:
- The equation \( \sum E = \sum IR \) represents the relationship between the total electromotive force (EMF) in a closed circuit and the total voltage drop across the resistors in that circuit.

2. **Identifying the Context**:
- This equation is related to electrical circuits, specifically in the context of Kirchhoff's laws, which govern the behavior of currents and voltages in electrical networks.

3. **Reviewing Kirchhoff's Laws**:
- Kirchhoff's laws consist of two main principles:
- **Kirchhoff's First Law (Junction Rule)**: The sum of currents entering a junction equals the sum of currents leaving the junction.
- **Kirchhoff's Second Law (Loop Rule)**: The sum of the EMFs in any closed loop is equal to the sum of the potential drops (voltage) across the resistors in that loop.

4. **Applying the Loop Rule**:
- The equation \( \sum E = \sum IR \) directly corresponds to Kirchhoff's Second Law (Loop Rule). It states that in a closed loop, the total EMF (sum of voltages supplied by batteries) is equal to the total voltage drop across the resistors.

5. **Conclusion**:
- Therefore, the equation \( \sum E = \sum IR \) is applicable to **Kirchhoff's Second Law**.

### Final Answer:
The equation \( \sum E = \sum IR \) is applicable to **Kirchhoff's Second Law**.

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