Understanding the Analogy Question

The question asks us to find the relationship between 'Chalk' that is similar to the relationship between 'Copper' and 'ductile'. This is a word analogy question where we need to identify the type of relationship in the first pair and apply the same relationship to the second part to find the missing word.

Analyzing the First Pair: Copper : ductile

Let's look at the relationship between Copper and ductile:

• Copper: Copper is a type of metal.
• Ductile: Ductility is a physical property of a material. A material is ductile if it can be drawn out into a thin wire without losing its toughness. Many metals, including copper, are known for being highly ductile.

So, the relationship here is that 'ductile' is a key physical property of 'Copper'.

Applying the Relationship to the Second Pair: Chalk : ?

Now we need to find a word that represents a key physical property of 'Chalk' from the given options.

• Chalk: Chalk is a soft, white, porous sedimentary rock, primarily composed of calcium carbonate. It is commonly used for writing on blackboards.

Let's examine the options provided:

1. white: White is the color of chalk. While it is a property, the analogy seems to focus on mechanical properties (how the material behaves under stress), like ductility for copper.
2. brittle: Brittleness is a physical property of a material. A material is brittle if it tends to break or fracture when subjected to stress, rather than bending or deforming significantly. Chalk is well-known for being brittle; it breaks easily.
3. soft: Softness is also a physical property. Chalk is relatively soft compared to many other materials. However, 'brittle' describes how it behaves under stress, which aligns more closely with 'ductile' (which describes how copper behaves under stress, i.e., stretching into wire).
4. writing: Writing is a common use of chalk, not a physical property of the material itself. The analogy requires a property, not a use.

Identifying the Correct Relationship for Chalk

Comparing the options and the relationship found in the first pair, 'brittle' is the physical property of chalk that is most analogous to 'ductile' being a physical property of copper. Copper is ductile (stretches), while chalk is brittle (breaks). Both describe the material's mechanical behavior.

Therefore, the relationship is: Copper is characterized by being ductile, and Chalk is characterized by being brittle.

Conclusion

Based on the analysis of the analogy, the word that completes the second pair is 'brittle', as it is a key physical property of chalk, similar to how 'ductile' is a key physical property of copper.

Revision Table: Key Concepts for Analogy

Additional Information: Properties of Materials

Understanding the physical and mechanical properties of materials is crucial for solving many analogy and reasoning questions. Here are a few related properties:

• Malleable: Ability of a material to be hammered or pressed permanently out of shape without breaking or cracking (e.g., gold, aluminum). Similar to ductile, but relates to compression rather than tension.
• Hardness: Resistance of a material to deformation, indentation, or scratching. (e.g., diamond is very hard).
• Elasticity: Ability of a material to return to its original shape after being deformed by stress (e.g., rubber).
• Tenacity (Toughness): Ability of a material to absorb energy and plastically deform without fracturing. Brittle materials have low toughness.

These properties describe how materials behave under different types of force and stress, providing common relationships used in analogy questions.