Find the fractional increase in volume of a wire of circular cross section if its longitudinal strain is `1% . (sigma=0.30)`

Explanation

we know that `(dV)/(V) = (dL)/(L) (1-2sigma)`
Here , `(dL)/(L) = 1% = 1/100 = 0.01 , sigma = 0.30`
The fractional increase in volume,
`(Delta V)/(V) = 0.01 (1-2 xx 0.30)`
` = 0.01 xx 0.40 = 0.004`