159) In counter-current flow heat exchanger, the logarithmic temperature difference between the fluids is __________ as compared to parallel flow heat exchanger.

same

less

greater

none of these

Answer is:

greater

these react with water vapour and cause acid rain

these react with plants and cause green-house effect

these react with oxygen and cause its depletion

these react with ozone layer

Answer is:

operating the machine at higher speeds

operating the machine at lower speeds

raising the higher temperature

lowering the higher temperature

Answer is:

low

high

normal

none of these

Answer is:

decrease in fin spacing and increase in number of rows

increase in fin spacing and increase in number of rows

increase in fin spacing and decrease in number of rows

decrease in fin spacing and decrease in number of rows

Answer is: