Two soil specimens with identical geometric dimensions were

Two soil specimens with identical geometric dimensions were subjected to falling head permeability tests in the laboratory under identical conditions. The fall of water head was measured after an identical time interval. The ratio of initial to final water heads for the test involving the first specimen was 1.25. If the coefficient of permeability of the second specimen is 5-times that of the first, the ratio of initial to final water heads in the test involving the second specimen is

Let coeff. of permeability of first specimen be k
∴ coeff of permeability of second specimen = 5 k
For falling head permeability test,

k = 2.303	aL	log₁₀		h₁
	At			h₂

For indential specimen,

k ∝ log₁₀			h₁
			h₂

∴	h₁	= 3.05
	h₂