`----------` of the following is not good conductor of electricity .

Options

A. Tap water
B. Vegetable oil
C. Vinegar
D. Lemon juice

Answer

To determine which of the following options is not a good conductor of electricity, we will analyze each option based on their properties related to electrical conductivity.

### Step-by-Step Solution:

1. **Understanding Conductors**:
- A good conductor of electricity is a substance that allows electric current to flow through it easily. This typically requires the presence of free ions or charged particles.

2. **Analyzing the Options**:
- **Option 1: Tap Water**:
- Tap water usually contains dissolved minerals and impurities, which provide free ions. Therefore, tap water is a good conductor of electricity.

- **Option 2: Vegetable Oil**:
- Vegetable oil is a non-polar substance and does not contain free ions or impurities. Thus, it does not conduct electricity well.

- **Option 3: Vinegar**:
- Vinegar is a solution of acetic acid, which dissociates into ions when dissolved in water. This means vinegar can conduct electricity, making it a good conductor.

- **Option 4: Lemon Juice**:
- Lemon juice contains citric acid, which also dissociates into ions in solution. Therefore, lemon juice can conduct electricity and is also a good conductor.

3. **Conclusion**:
- Among the options provided, vegetable oil is the only substance that does not have free ions or impurities to conduct electricity. Therefore, the correct answer is **vegetable oil**.

### Final Answer:
**Vegetable oil** is not a good conductor of electricity.

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