Q1: Increasing the temperature of a material makes it

ANS:B - softer

Increasing the temperature of a material typically makes it softer. Explanation:

1. Effect of Temperature on Material Properties:
   • Hardness: Generally, increasing the temperature of a material tends to decrease its hardness. This is because elevated temperatures can disrupt the crystal lattice structure of the material, reducing its resistance to indentation or scratching.
   • Softness: Higher temperatures often lead to increased atomic mobility within the material, allowing atoms to move more easily past each other. As a result, the material becomes softer and more ductile.
   • Toughness: Toughness is the ability of a material to absorb energy and deform plastically before fracturing. The effect of temperature on toughness can vary depending on the material and its microstructure. In some cases, increasing temperature may improve toughness by increasing ductility, while in others, it may decrease toughness due to changes in microstructural properties.
   • Strength: The effect of temperature on strength can also vary depending on the material. In some materials, such as metals, increasing temperature can lead to a decrease in strength due to reduced dislocation density and increased atomic mobility. However, in certain materials like polymers, strength may increase with temperature up to a certain point before decreasing due to thermal degradation.
2. Examples:
   • Metals: In metals, increasing temperature typically leads to a decrease in hardness and strength due to thermal activation of dislocations and grain boundary movement, resulting in increased ductility and decreased resistance to deformation.
   • Polymers: In polymers, increasing temperature can lead to increased chain mobility, which may enhance toughness and ductility but can also lead to thermal softening and reduced strength at higher temperatures.
   • Ceramics: The effect of temperature on ceramics can vary widely depending on factors such as composition, microstructure, and processing methods. In general, ceramics tend to maintain their hardness and strength at elevated temperatures but may experience reduced fracture toughness due to thermal stresses.