For which of the following materials, the output of power shovels for a fixed shovel size will be maximum?

The production of a power shovel is depend on four major factors: Bucket Size, Bucket Fill factor, cycle time and efficiency.

Since the Bucket Size is fixed and assuming that the cycle time and efficiency of work are also constant, we have to compare the bucket fill factor of each material.

the moist loam and the common earth fall in the same category and have a factor ranging between 0.8 and 1.1

the well blasted rock has a factor ranging between 0.7 and 0.9

finally clay is usually divided to two categories, hard clay and wet clay, the wet clay has a factor ranging between 0.5 and 0.9

we can conclude that the power shovel can have a maxiumum output when working with common earth or moist loam.

(All of these ranges and factors are available in performance handbooks or estimating books)

I agree with the answer fellow trainee / Riad Boughannam

Thans you for the invitation