Question

A sprayer having 0.4 litre per minute nozzle discharge rate and 50 cm width of coverage, is required to apply 0.8 kg of active ingredient per hectare. If one kg of active ingredient is contained in 120 litres of spray solution, determine the speed of the sprayer.

(a) 4 km/h

(b) 3 km/h

(c) 5 km/h

(d) 6 km/h

I got this question at a job interview.

This key question is from Plant Protection Equipments topic in chapter Plant Protection Equipments of Farm Machinery

Answer 1

The correct option is (c) 5 km/h

Explanation: 1 kg active ingredient is dissolved in 120 L water

0.8 kg active ingredient is dissolved in 120 * 0.8 = 96 L

Application rate = 96 L/ha

Area covered = \(\frac{0.5*s}{10} \) ha/h

Time required to cover one ha land = \(\frac{10}{0.5*s} \) h

Time required to spray one ha land = \(\frac{96}{0.4*60} \) h

Equating,

\(\frac{10}{0.5*s}\) h = \(\frac{96}{0.4*60} \)h

S = 5 km/h