Question

definition of poison and ratio class 12​

Answer 1

poison a substance that cause disturbance in organism usually by chemical reaction or other activity on the molecular weight scale when an organism observe and sufficient quantity

Answer 2

if wire's basic diameter would d and diameter deacresing by (delta)d then Lateral strain will be (delta)d/d. if wire's basic length is l would l and it is increasing by stress is (delta)l then similar strain is (delta)l/l

then poisson's ratio will be

$\frac{(delta)d \times l}{d \times (delta)l}$

poisson's ratio is ratio of two strains. it is only number form. this ratio hasn't any unit or MLTs.