The correct option is (a) \(F_e \sqrt{P_e}=(F_1+F_2)\sqrt{P} \)
The explanation is: The equivalent wheel load Pe is given by,
\(F_e \sqrt{P_e}=(F_1+F_2)\sqrt{P},\)
Where, Pe=equivalent wheel load
P=wheel load of each of the dual tyres
Fe=settlement factor for equivalent wheel load
F1= settlement factor contributed by one tyre of the
F2= settlement factor contributed by other tyre.