Pakistan's MCQ Practice Library for Competitive Exams

A. The shear stress at any given cross-section of a pipe for steady flow (either laminar or turbulent) varies linearly as the radial distance

B. The form drag is dependent upon the occurrence of a wake

D. Existence of the boundary layer in fluid flow is because of viscosity of the fluid.

B. Organic pigments are used as colouring materials in the soap manufacture

C. Both laundry as well as toilet soaps are manufactured by hot process

D. Colourless rosin is used in the manufacture of laundry soaps

A. Steam is fed to the shell, whereas the liquor is filled inside the tube

B. Tube dia is 3-6 cms, while tube length in 3-6 metres

D. Liquor level is maintained at 1/3rd to 1/2 of the height of the tube

A. Its usual dimensions are: tube dia = 2-3 cms; evaporator body dia = 1-4 metres and evaporator

B. ght = 2.5-4 metres

C. It is suitable for process, in which the final product is a liquor instead of solid

D. It is unsuitable for concentrating those liquids, which form a scale or deposit salt

A. Increases with the increasing flake size keeping the flake thickness constant

B. Decreases with decrease of thickness of the flakes

C. Increases considerably with the rise of temperature

A. Increases with the increasing flake size keeping the flake thickness constant

B. Increases considerably with the rise of temperature

D. Decreases with decrease of thickness of the flakes

A. e ultra-violet rays) to pass through the glass and heat up the soil thereby warming up plants

B. the glass of the green house

C. Green house (made of glass) allows visible sunlight (i.e., short wavelength solar radiation

D. ide it

E. acts like the glass of green house thereby warming up the earths surface

F. Green house effect in earths atmosphere is due to increasing CO2 level in atmosphere, where

A. Decreases with increase in hardness, in general

B. Decreases with increase in strain hardening tendencies

D. Depend on the composition, microstructure and physical & mechanical properties

A. The viscous fluid should be routed through the shell side

B. The corrosive and fouling fluid should be preferably routed through the tubes

D. Lower flow rate fluid should be routed through the shell side

A. In differential (simple) distillation, the vapour is removed as soon as it is formed without appreciable condensation

B. Distillation under vacuum is a substitute for steam distillation

D. In flash (equilibrium) distillation, a definite fraction of liquid is vaporised in such a way that the evolved vapour & residual liquids are in equilibrium with each other

A. A horizontal line on the humidity chart indicates the temperature changes at constant molal

B. idity

C. When water is cooled from 80 to 70C by exposure to the air with a wet bulb temperature of

D. C, then both the approach & the range would be 10C

E. For unsaturated air-water vapor mixture at atmospheric conditions, the wet bulb temperature

F. p; adiabatic cooling lines are the same

A. Polythene is a copolymer, while SBR is a homopolymer

B. Protein is a natural polymer

D. Polystyrene is a thermoplastic polymer

B. One important copolymer of styrene is SBR, which is widely used in the manufacture of

C. For the manufacture of styrene, the major raw materials are benzene and ethylene

D. Manufacture of phenol by chloroben-zene-eaustic process involves. The chlorination of benzene, causticisation and hydrolysis

E. omobile tyres

A. Momentum transfer in laminar flow results from velocity gradient

B. A fluid in equilibrium is not free from shear stress

C. The viscosity of a non-Newtonian fluid is a function of temperature only

A. Characterisation factor of paraffinic crude oil is more than 12

B. Pensky-Marten apparatus is used for determining flash points above 50C

C. Abel apparatus is used for determining flash points below 50C

A. The ratio of immediately available cash to the total current liabilities is known as the cash

B. io

C. Gross revenue is that total amount of capital received as a result of the sale of goods or service

E. ws the relationship among total income, costs & profit over the time interval

F. Consolidated income statement based on a given time period indicates surplus capital and

A. estment

B. Annual depreciation rate of buildings in a chemical plant is about 3% of its initial cost

C. Insurance rates on annual basis in a chemical plant may be about 1% of the fixed capital

D. ut 10% of the fixed capital investment

E. lisation (NSR)</strong>

F. The annual depreciation rate for machinery and equipments in a chemical process plant is

A. Value of Stefan-Boltzmann constant is 4.876 10-8 KCal/m2.hr.K4

B. Absorptivity of a body approaches unity in case of diffuse reflection

D. Absorptivity of a perfectly black body is unity

A. Phase change in case of a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature

B. The controlling resistance in case of heating of air by condensing steam is in the air fil

C. The log mean temperature difference (LMTD) for counter flow and parallel flow can be theoretically same when any one of the fluids (hot or cold fluid) passes through the heat exchanger at constant temperature

D. rply, when a temperature cross occurs</strong>

A. Both annealing and normalising release the internal stresses of the material besides improving

B. mechanical properties

C. Low carbon steel does not respond to the heat treatment for hardening of the material, hence it

D. subjected to case hardening or surface hardening processes like cyaniding, carburising,

E. riding etc., which produces high carbon outer layers resulting in increase of surface

F. dness