Question

The length and breadth of a rectangle are (5.7 ± 0.1) cm and (3.4 ± 0.2) cm. Calculate the area of the rectangle with error limits. 

Answer 1

I = (5.7 ± 0.1) cm

b = (3.4 ± 0.2) cm

Area = lb = 5.7 × 3.4 = 19.38 cm²

ΔA/A = (ΔI/I) + (Δb/b)

⇒ ΔA = ((0.1/5.7) + (0.2/3.4)) × 19.4

= 1.5 cm²

∴ A = (19.4 ± 1.5) cm²