Physics · Class 11 · Chapter 8
Mechanical Properties of Solids
9 lessons 79 min 2 simulations
No solid is perfectly rigid: forces stretch, shear and squeeze it. This chapter measures the deforming force as stress and the response as strain, follows a metal wire along its stress-strain curve from Hooke's law to fracture, defines the three elastic moduli (Young's, shear and bulk) with Poisson's ratio and stored elastic energy, and then uses them to size crane ropes, shape beams and estimate how tall a mountain can be.
What the exam asks
NEET asks for elongation from Y = FL/(AΔL), wires joined in series or loaded differently, the regions and points of the stress-strain curve (elastic limit, permanent set, brittle versus ductile), bulk modulus and compressibility from pressure and volume change, Poisson's ratio and the energy stored per unit volume, ½ × stress × strain. Marks are lost by using diameter as radius, forgetting to convert mm² or cm² to m², mixing up which strain goes with which modulus, and calling rubber more elastic than steel.
Lessons
9 lessons · 79 min
1Elasticity and plasticityNCERT §8.16 min2Stress and strainNCERT §8.27 min3Hooke's law and the stress-strain curveNCERT §8.3, §8.410 min 1 sim4Young's modulusNCERT §8.5.18 min5Shear modulusNCERT §8.5.26 min6Bulk modulus and compressibilityNCERT §8.5.37 min7Poisson's ratio and elastic energyNCERT §8.5.4, §8.5.56 min8Applications of elastic behaviourNCERT §8.612 min 1 sim9Chapter reviewMust-know facts, traps and formulas17 min