Question

Calculate the time required to sow 10.8 hectare field, if a seed drill consists of 9 furrow openers for dropping seeds and working efficiency of drill is 80%. Assume that furrow openers are 20 cm apart from one another and working speed is 5 km.h\(^{-1}\).

• A. 5 h
• B. 9 h
• C. 10 h
• D. 15 h

Hint:

Remember:
Width = no. of furrow openers \(\times\) spacing.
Efficiency is multiplied with the theoretical area.
Always convert hectares to m\(^2\).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
We need to calculate the time required for sowing.
We have the field area, number of furrow openers, spacing, speed, and efficiency.

Step 2: Key Formula or Approach:
Effective width of drill = Number of furrow openers \(\times\) Spacing.
Area covered per hour = Width \(\times\) Speed \(\times\) Efficiency.
Time required = Total area Area covered per hour.

Step 3: Detailed Explanation:
Width = 9 openers \(\times\) 20 cm = 180 cm = 1.8 m.
Speed = 5 km/h = 5000 m/h.
Theoretical area covered per hour = Width \(\times\) Speed = 1.8 \(\times\) 5000 = 9000 m\(^2\)/h.
But efficiency = 80%.
Actual area covered per hour = 0.8 \(\times\) 9000 = 7200 m\(^2\)/h.
Total area = 10.8 hectare = 10.8 \(\times\) 10000 = 108000 m\(^2\).
Time = 108000 7200 = 15 hours.

Step 4: Final Answer:
The time required is 15 hours.
Hence, the correct option is (D).