ANS:A - increase

When the amount of liquid used in an absorber is decreased, the tower height will typically decrease. Here's why: In an absorber, the liquid serves to absorb or capture the desired component(s) from the gas stream. The efficiency of this absorption process depends on several factors, including the contact time between the gas and liquid phases and the mass transfer rate between them. When the amount of liquid used in the absorber is decreased:

• The contact time between the gas and liquid phases may decrease.
• There may be fewer opportunities for the desired components in the gas phase to come into contact with the liquid phase for absorption.
• As a result, the tower height needed to achieve the desired level of absorption may decrease.