Alloys are best prepared by

Analysis of the Question

The question asks for the most effective method used to prepare alloys. An alloy is a homogeneous mixture of two or more metals (or a metal and a non-metal). To create this mixture, the components must be thoroughly combined at a molecular level.

Concept Explanation

An alloy is formed by combining metals in their molten (liquid) state. When metals are heated until they melt, their atoms gain enough kinetic energy to move freely. By mixing these molten metals together and then allowing the mixture to cool and solidify, the atoms become uniformly distributed throughout the solid structure. This process ensures the resulting material has the desired physical and chemical properties (like increased strength or corrosion resistance).

Step-by-Step Solution

1. Evaluate Option A (Electroplating): This is a process used to coat one metal with another using electricity. It does not create an alloy; it creates a surface layer.
2. Evaluate Option B (Arc-welding): This is a technique used to join two pieces of metal together using heat from an electric arc. While it involves melting, it is a joining process, not a method for creating a bulk alloy.
3. Evaluate Option C (Reducing and mixture of their metallic): This phrasing is grammatically incorrect and scientifically inaccurate. Reduction is a process used to extract metals from their ores, not to mix them into alloys.
4. Evaluate Option D (Cooking a molten of the metals): In chemistry, "cooking" in this context refers to the process of melting the metals together in a furnace (often called "melting" or "fusion"). By melting the constituent metals and stirring them together, you create a uniform liquid solution that forms an alloy upon cooling.

Conclusion

The most accurate way to describe the preparation of an alloy is by melting the metals together. While the phrasing in option D is slightly informal ("cooking"), it is the only option that correctly describes the process of fusion (melting) to create a metallic mixture.

Exam Tip: Whenever you see questions about alloys, remember the keyword "Fusion." Alloys are almost always prepared by the fusion of the constituent metals. If you see "melting" or "fusion" in the options, that is almost certainly your correct answer.