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The heat released by cooling one mole of copper from 400 K to room temperature (300 K) is (assume : Cp of copper is 23 J K-1mole-1)

A. 2300 J

B. 4600 J

C. 230 J

D. 2.3 × 106 J

Correct Answer :

A. 2300 J


Related Questions

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The escape velocity of a body on earth which is independent of its mass is about __________ km/second.

A. 3

B. 7

C. 11

D. 15

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Coating provided on the electrodes used in the arc welding is not expected to

A. Add alloying elements

B. Prevent electrode from contamination

C. Stabilise the arc

D. Provide protective atmosphere to weld

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4

Metal shots used in shot blasting are made of

A. Stellite

B. Steel

C. Bronze

D. Lead

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Potable water means the water used for

A. Fire-fighting

B. Cooling

C. Drinking

D. Evaporation to produce steam

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Pick out the wrong statement.

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

B. Low carbon steel does not respond to the heat treatment for hardening of the material, hence it is subjected to case hardening or surface hardening processes like cyaniding, carburising, nitriding etc., which produces high carbon outer layers resulting in increase of surface hardness

C. Induction hardening and flame hardening techniques are also used for surface hardening

D. Martempering of a material is a hardening process

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Which of the following phenomenon will exhibit the minimum heat transfer?

A. Boiling

B. Forced convection in air

C. Free convection in air

D. Conduction in air

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The yield point phenomenon observed in annealed low carbon steel is due to the presence of the following element.

A. Silicon

B. Carbon

C. Phosphorous

D. Chromium

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4

Cold chisel & hammers are made of

A. High speed steel

B. High carbon steel

C. Forged steel

D. Mild steel

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4

A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place

A. The better insulation material should be put just next to pipe (i.e., inside)

B. The better insulating material should be put outside

C. Either of the insulating material could be put on either side

D. Steam temperature is considered before deciding as to which insulating material is to be put inside (i.e., just next to the pipe)

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4

Which of the following is the most wear resistant grade of carbide used for the cutting tools?

A. Aluminium carbide

B. Tungsten carbide

C. Nickel carbide

D. Iron carbide

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4

Use of water as a manometric liquid suffers from the disadvantage of its

A. Low vapour pressure

B. Corrosive nature

C. High vapour pressure

D. High boiling point

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In a boundary layer developed along the flow, the pressure decreases in the downstream direction. The boundary layer thickness in this case will

A. Decrease gradually

B. Increase gradually

C. Increase rapidly

D. Remain constant

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4

Air standard Otto cycle is more efficient than the diesel cycle for the same

A. Heat addition & compression ratio

B. Heat addition & pressure

C. Compression ratio & pressure

D. Cylinder dimension & rpm

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4

Air/fuel ratio by weight for combustion of methane with theoretical quantity of air will be about

A. 9 : 1

B. 17 : 1

C. 23 : 1

D. 29 : 1

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In a neutral solution

A. H+ ions are absent

B. OH- ions are absent

C. Both H+ and OH- ions are present in very small but equal concentration

D. None of these

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The 'transition temperature' for ductile to brittle behaviour of steel increases with increase in the __________ content in steel.

A. Carbon

B. Manganese

C. Both 'a' nor 'b'

D. Neither 'a' nor 'b'

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Difference at any instant between the value of the controlled variable and the set point is called the

A. Deviation

B. Derivative time

C. Error ratio

D. Differential gap

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__________ pipe is the most suitable for carrying sanitary drainage.

A. Stainless steel

B. Reinforced cement concrete

C. Cast iron

D. Asbestos cement

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4

The wet bulb temperature is lower in dry air than in wet air at the same temperature. A dry bulb thermometer registers a higher temperature than a wet bulb thermometer except at __________ percent relative humidity.

A. 0

B. 100

C. 50

D. None of these

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4

Out of the following, maximum temperature drop for a given heat flow & for the same thickness will be in the case of

A. Steel

B. Glass wood

C. Copper

D. Fireclay bricks

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A thin, flat & square plate measuring 2 m × 2 m is freely hanging in ambient air at 25°C. It is exposed to the solar radiation falling on one side of the plate at the rate of 500 W/m2. The plate temperature will remain constant at 30°C, if the convective heat transfer co-efficient is __________ W/m2 °C.

A. 50

B. 100

C. 150

D. 200

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Nusselt number/Biot number varies

A. Inversely with thermal conductivity

B. Directly with heat transfer co-efficient

C. Directly with thermal conductivity

D. Inversely with the dimension of the solid

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4

For separating small pieces of metal from engine oil of a car, the best separating technique is the

A. Chromatography

B. Evaporation

C. Filtration

D. Fractional distillation

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4

Which of the following can be manufactured using powder metallurgy techniques?

A. Brake linings

B. Bearings

C. Carbide tool tips

D. All 'a', 'b' and 'c'

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Strain hardening effect in metals subjected to cold working is due to the __________ mechanism.

A. Slip

B. Fracture

C. Winning

D. Dislocation

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4

What happens, when SO2 is passed through a solution of H2S in water?

A. Precipitation of sulphur takes place

B. H2SO3 is formed

C. Oleum is formed

D. None of these

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4

Gage pressure within a spherical droplet of a fluid is 'p'. What will be gage pressure within a bubble of the same size & of the same fluid?

A. p

B. 2 p

C. 0.5 p

D. 0.25 p

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The specific gravity of coal depends mainly on its __________ content.

A. Carbon

B. Volatile matter

C. Ash

D. Moisture

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If Reynolds number is greater than 1, then the

A. Viscous force is larger than the inertia force

B. Inertia force is larger than the viscous force

C. Inertia force is larger than the surface tension force

D. Inertia force is larger than the gravitational force

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Lead pencil contains

A. Graphite

B. Lead sulphide

C. Lead

D. Both (B) & (C)