Explain how electron mobility changes for a good conductor, when (i) the temperature of the conductor is decrased at constant potential difference and (ii) applied potential difference is doubled at constant temperature.

Explanation

To solve the question regarding how electron mobility changes for a good conductor under two different scenarios, we will break it down step by step.

### Step 1: Understanding Electron Mobility
Electron mobility (μ) is defined as the drift velocity (v_d) of electrons per unit electric field (E). Mathematically, it can be expressed as:
\[ \mu = \frac{v_d}{E} \]

### Step 2: Analyzing the Effect of Temperature Decrease
(i) **When the temperature of the conductor is decreased at constant potential difference:**
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