The idea of displacement current was introduced by

Options

A. Hertz
B. Maxwell
C. JC Bose
D. Marconi

Answer

To solve the question regarding who introduced the idea of displacement current, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept**: Displacement current is a term used in Maxwell's equations to describe a quantity that accounts for the changing electric field in regions where there is no conduction current.

2. **Identify the Scientists**: The question provides four options:
- Hertz
- Maxwell
- JC Bose
- Marconi

3. **Recall Historical Contributions**:
- Heinrich Hertz is known for his work in electromagnetic waves.
- James Clerk Maxwell is known for formulating the set of equations that describe electromagnetism, including the concept of displacement current.
- Jagadish Chandra Bose contributed to radio and microwave optics.
- Guglielmo Marconi is known for his work in radio transmission.

4. **Select the Correct Option**: Based on historical knowledge, the concept of displacement current was indeed introduced by James Clerk Maxwell.

5. **Final Answer**: Therefore, the correct answer to the question is **Maxwell**.