The longitudinal strain in a metal bar is 0.5. If the Poisson's ratio for the metal is 0.20, then the lateral strain is ______ mm.
Physics · Mixed Chapter
JEE Main Practice

Question

The longitudinal strain in a metal bar is 0.5. If the Poisson's ratio for the metal is 0.20, then the lateral strain is ______ mm.

G1 Physics · Accepted Answer

Step 1: Poisson's ratio ν = −εₗₐₜ/εₗₒₙg. Step 2: Hence εₗₐₜ = −νεₗₒₙg = −0.20 × 0.5 = −0.10. Step 3: The magnitude of lateral strain is 0.1; it has no unit because strain is a ratio. Step 4: The original question incorrectly appends 'mm' to lateral strain. A lateral *change in width* in mm would require initial width, which is not supplied. Source-key magnitude: 0.1 (dimensionless); source unit 'mm' is incorrect.