The conducting medium in which flow of positive ions and negative ions develop currnt through the medium is known as

Options

A. Metal
B. Semiconductor
C. Electrolyte solution
D. Insulators

Answer

To solve the question regarding the conducting medium where the flow of positive ions and negative ions develops current, we can analyze the options provided step by step.

### Step 1: Understand the Options
We have four options to consider:
1. Metal
2. Semiconductor
3. Electrolyte solution
4. Insulator

### Step 2: Analyze Each Option
- **Metal**: In metals, the conduction of electricity is primarily due to the flow of electrons. Metals do not involve the movement of positive and negative ions to conduct current. Therefore, this option is incorrect.

- **Semiconductor**: In semiconductors, conduction occurs due to the movement of electrons and the presence of holes (vacancies left by electrons). While there is some ionic movement in certain conditions, it is not the primary mechanism for current flow in semiconductors. Thus, this option is also incorrect.

- **Electrolyte Solution**: An electrolyte solution consists of ions that can move freely. When an electric field is applied, positive ions (cations) move towards the negative electrode, and negative ions (anions) move towards the positive electrode. This movement of ions constitutes an electric current. Therefore, this option is correct.

- **Insulator**: Insulators do not allow the flow of electric current as they do not have free charge carriers. Hence, this option is incorrect.

### Step 3: Conclusion
Based on the analysis, the correct answer is:
**Option C: Electrolyte solution**.