Chemical Engineering Basics
The emf of a Deniell cell Zn | Zn²⁺ || Cu²⁺ | Cu can be increased by

Increasing the concentration of copper sulphate solution
Increasing the concentration of zinc sulphate solution
Increasing the surface area of the electrodes
Decreasing the surface area of the electrodes

ANSWER DOWNLOAD EXAMIANS APP

Chemical Engineering Basics
What is the effect on the performance of the economiser in the thermal power plant boiler, if the feed water temperature is very low due to preheaters being out for repairs or starving of steam supply ?

Heat transfer efficiency of economiser increases due to picking up high heat from the flue gases
Economiser tube life increases due to handling of low temperature water
Scale formation rate on economiser tubes increases
It results in corrosion due to the condensation on the flue gas side of the economiser tubes due to handling of low temperature water

ANSWER DOWNLOAD EXAMIANS APP

Chemical Engineering Basics
Which of the following is not a characteristic observed in material failure by fatigue fracture ?

Plastic deformation of material does not occur
Initiation of crack from below the surface does not occur
Initation of crack occurs on the surface of the machine part
Presence of both rough & smooth zone with conchoidal markings in smooth zone of the surface

ANSWER DOWNLOAD EXAMIANS APP