Q1: Reduction in the grain size reduces the __________ of the material.

ANS:D - all (a), (b) & (c)

Reduction in the grain size reduces all of the following properties of the material:

1. Fatigue Resistance: Fatigue resistance refers to the ability of a material to withstand repeated cyclic loading without failure. When the grain size is reduced, the material's resistance to fatigue decreases because smaller grains provide more sites for crack initiation and propagation, leading to premature failure under cyclic loading conditions.
2. Tensile Strength: Tensile strength is the maximum stress a material can withstand under tension before it fails. When the grain size is reduced, the material's tensile strength typically decreases because smaller grains have more grain boundaries, which act as sites for deformation and crack propagation, resulting in lower overall strength.
3. Creep Resistance: Creep resistance is the ability of a material to resist deformation under long-term, constant stress at elevated temperatures. Reduction in grain size often reduces creep resistance because smaller grains allow for faster diffusion of atoms along grain boundaries, leading to increased creep deformation at lower stresses and temperatures.