A two-wheel drive tractor weighing 18 kN has a wheel base 1.8 m. Its centre of gravity is located 600 mm ahead of the rear axle centre, under static condition, on a level ground. When this tractor is used to pull a disc plough hitched at a height of 390 mm from the ground, the draft observed is 6 kN. The change in reaction on rear wheels of the tractor due to pull in kN is
Options:
(A) 1.30
(B) 1.95
(C) 3.90
(D) 5.85
Official Answer Key:
A
Step-by-Step Solution & Explanation
Taking moments about the rear-axle contact point, the pull P acting at height h transfers weight from front to rear.
ΔR_rear = P × h / L, where L = wheelbase.
= 6 × 0.390 / 1.8 = 2.34/1.8 = 1.30 kN (increase on rear wheels; the front reaction drops by the same amount).
Distractor (C) 3.90 comes from using the CG distance (0.6 m) instead of the wheelbase in the denominator.
Practice This in Real CBT Exam Interface
Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.