Lead is used for making fusible alloy constituted of lead and tin in ________ ratio by mass.

Options

A. `1 : 2`
B. ` 2 : 1`
C. ` 1: 3`
D. ` 1 : 1`

Explanation

To solve the question regarding the ratio of lead and tin used to make a fusible alloy, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the ratio of lead to tin in a fusible alloy. A fusible alloy is a mixture of metals that has a low melting point.

2. **Identify the Components**: The two metals mentioned are lead and tin. We need to find out in what ratio they are combined to form the fusible alloy.

3. **Research the Properties**: Fusible alloys are often used in applications like fuses in electrical circuits. They are designed to melt at specific temperatures to prevent damage to electrical devices.

4. **Determine the Common Ratio**: It is known that a common ratio for lead and tin in a fusible alloy is 1:1. This means equal parts of lead and tin are used.

5. **Select the Correct Option**: Given the options:
- 1:2
- 2:1
- 1:3
- 1:1

The correct ratio for the fusible alloy of lead and tin is 1:1.

6. **Conclusion**: Therefore, the answer to the question is that lead is used for making a fusible alloy constituted of lead and tin in a **1:1 ratio by mass**.

### Final Answer:
Lead is used for making a fusible alloy constituted of lead and tin in **1:1 ratio by mass**.

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