Question

Match List-I with List-II

List-I	List-II
(A) Falling rate period	(I) Ratio of humidity with respect to humidity at saturation point
(B) Absolute humidity	(II) Critical moisture content
(C) Percent humidity	(III) Equilibrium moisture content
(D) Constant rate period	(IV) Ratio of kg of water vapour in kg of dry air

Choose the correct answer from the options given below:

• A. (A)-(I), (B)-(II), (C)-(III), (D)-(IV)
• B. (A)-(III), (B)-(IV), (C)-(II), (D)-(I)
• C. (A)-(I), (B)-(II), (C)-(IV), (D)-(III)
• D. (A)-(III), (B)-(IV), (C)-(I), (D)-(II)

Hint:

Work out the two humidity terms from their plain definitions first, then think about which drying period ends at critical moisture content and which one ends at equilibrium moisture content.

Answer 1

The Correct Option is D

Split the four terms into two humidity terms and two drying period terms and handle each pair separately.

For humidity: absolute humidity is a straight mass ratio, water vapour mass over dry air mass, no comparison to saturation involved, so it must be (IV). Percent humidity, by contrast, is defined by comparing the actual humidity ratio to the saturated humidity ratio at the same temperature, so it must be (I).

For the drying periods: picture a moisture content versus time curve. Drying starts in the constant rate period, moves in a straight line down to a point called the critical moisture content, this handover point is what (D) constant rate period is tied to, so (II). Past that point the curve bends and flattens out slowly, approaching but never quite reaching the equilibrium moisture content, which is the falling rate period's defining limit, so (A) pairs with (III).

Both approaches land on the same pairing, A-(III), B-(IV), C-(I), D-(II).

\[ \text{Correct match} = \text{Option 4} \]