The solids which are good conductor of electricity should have conductivities in the order of

Options

A. `10^(7)Omega^(-1)m^(-1)`
B. `10^(-20)Omega^(-1)m^(-1)`
C. `10^(-6)Omega^(-1)m^(-1)`
D. `10^(4)Omega^(-1)m^(-1)`

Answer

To solve the question regarding the order of conductivity for good conductors of electricity, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Conductivity**: Conductivity is a measure of a material's ability to conduct electric current. Good conductors allow electric current to pass through them easily.

2. **Identify Good Conductors**: Metals are typically considered good conductors of electricity. This is because they have free-moving electrons that facilitate the flow of electric current.

3. **Know the Order of Conductivity**: The conductivity of metals is generally in the range of \(10^7 \, \text{ohm}^{-1} \, \text{m}^{-1}\). This means that good conductors have a high conductivity value.

4. **Evaluate the Given Options**:
- \(10^7 \, \text{ohm}^{-1} \, \text{m}^{-1}\)
- \(10^{-20} \, \text{ohm}^{-1} \, \text{m}^{-1}\)
- \(10^{-6} \, \text{ohm}^{-1} \, \text{m}^{-1}\)
- \(10^4 \, \text{ohm}^{-1} \, \text{m}^{-1}\)

5. **Select the Correct Option**: Among the options provided, \(10^7 \, \text{ohm}^{-1} \, \text{m}^{-1}\) is the only value that corresponds to the conductivity of good conductors (metals).

6. **Conclusion**: Therefore, the correct answer is \(10^7 \, \text{ohm}^{-1} \, \text{m}^{-1}\).

### Final Answer:
The solids which are good conductors of electricity should have conductivities in the order of \(10^7 \, \text{ohm}^{-1} \, \text{m}^{-1}\).

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