The actual length, breadth and thickness ℓ, b and h of a rectangular slab are 0.2 m, 0.12 m and 0.13 m respectively. If ' ℓ ' is measured by a…

The actual length, breadth and thickness $\displaystyle \ell, \mathrm{b}$ and h of a rectangular slab are $\displaystyle 0.2$ m, $\displaystyle 0.12$ m and $\displaystyle 0.13$ m respectively. If ' $\displaystyle \ell$ ' is measured by a vernier callipers (zero is on the right of the main scale zero and $\displaystyle 8^{\text {th }}$ vernier division coincides with main scale division when its jaws coincide with each other) 'b' and 'h' are measured by another vernier scale ( $\displaystyle 4^{\text {th }}$ vernier division coincide with the main scale but zero on vernier shifts towards left when jaws are closed). The least count for both is $\displaystyle 0.01$ cm . What is the positive and negative zero error of the instruments ( in cm ) respectively.