Draw `E-r` and `V-r` graphs due to two point charges `+ q` and `-2q` kept at some along the line joining these two charges.

Explanation

To solve the problem of drawing the `E-r` (Electric Field vs. Distance) and `V-r` (Electric Potential vs. Distance) graphs due to two point charges `+q` and `-2q` kept at some distance along the line joining these two charges, we will follow these steps:

### Step 1: Understand the Configuration
We have two point charges:
- Charge 1: `+q`
- Charge 2: `-2q`

These charges are placed at a distance apart. We will analyze the electric field and potential at different points along the line joining the two charges.
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