With increase in temperature, the surface tension of water
Increases
Decreases
Remain constant
Increases linearly
Correct Answer :
B. Decreases
Related Questions
Identify the correct statement.
Sphlerite is zinc oxide
The first law of the thermodynamics is stated as δE = δQ - δW
Lead can be produced in a blast furnace
T. ferrooxidans is a fungus that can be used for leaching chalcopyrite
Lap joints are preferred over butt joints in soldering/brazing, because these joints are
Weaker in tension but stronger in shear
Weaker in shear but stronger in tension
Stronger in both shear and tension
The lap joints are easily made
A solid aluminium ball, when quenched in a water bath maintained at 40°C, cools down from 550°C to 450°C in 20 seconds. The expected temperature of the ball after next 20 seconds may be about __________ °C.
370
340
320
300
__________ temperature remains constant during adiabatic saturation process of unsaturated air.
Dew point
Dry bulb
Wet bulb
None of these
The escape velocity of a body on earth which is independent of its mass is about __________ km/second.
3
7
11
15
Primary designation of steel is based on its
Hardness & tensile strength
Carbon content
Iron content
Alloying elements content
Spheroidising of a material is a/an __________ process.
Normalising
Annealing
Tempering
Hardening
Super conduction in metals is observed at a temperature of __________ °K.
<100
>100
About 273
About 373
In a counter flow heat exchanger, hot fluid enters at 170°C & leaves at 150°C, while the cold fluid enters at 50°C & leaves at 70°C. The arithmetic mean temperature difference in this case is __________ °C.
20
60
120
∞
Alumina, silica, lime and iron oxide are the basic raw material for the manufacture of Portland cement. The component of Portland cement which first hardens is
Specific __________ is a dimensionless quantity.
Heat
Humidity
Weight
None of these
Which of the following approaches the ideal gas behaviour most closely?
Wet steam
Saturated steam
Superheated steam
Saturated water
In the diving apparatus, helium is used along with oxygen, because it is
Easily available
Not soluble in blood at high pressure
Lighter than nitrogen
Completely miscible with oxygen
If a solid is compressed adiabatically in its elastic range, its __________ remains constant
Internal energy
Enthalpy
Entropy
Temperature
Working of linear variable differential transducer (LVDT) is based on the principle of variable
Capacitance
Resistance
Mutual inductance
None of these
For the irreversible reaction, Ca+ 2C = Ca C2 , Δ H°298 = - 60000 J . mole-1 . If a system initially containing 2 moles of calcium, 3 moles of carbon and 1 mole of calcium carbide is allowed to react to completion, the heat evolved at 298 K will be
30,000 J
60,000 J
90,000 J
2,40,000 J
__________ is used for tying the steel columns to concrete foundation.
Grouting
Eyebolt
Anchor bolts
Refractory castables
Pick out the wrong statement about coating/electroplating of metals.
Phosphate coating is used as an excellent base for paints & enamels
Phosphate coating is less corrosion resistant than chromate coating
The base metal to be electroplated is normally made the cathode of the electrolytic cell and coating metal is made the anode
Calorising is the process of coating steel with chromium
Cold heading or upsetting is categorised as the __________ process.
Extrusion
Bending
Rolling
Forging
Though tin occurs lower than iron in the electrochemical series, yet it is coated on steel for corrosion protection, because of its
Lower cost
Abundant availability
Resistance to vegetable acids as the tin plate are commercially used in 'canning' industry
None of these
Function of gear box is to
Reduce the speed
Obtain variable speed
Increase the speed
Produce high torque
The phenomenon occurring during explosion of a hydrogen bomb is
Nuclear fission
Nuclear fusion
A combination of both nuclear fission & fusion
None of these
Pick out the wrong statement.
Geothermal energy is a non-conventional source of energy
Mass is converted into energy in both nuclear fission & fusion reaction
Inhalation of mercury vapour is not harmful for human beings
Inhalation of arsenic causes cancer
An alloy of Fe - 0.4 % C is
Cast iron
Hypo-eutectoid steel
Hyper-eutectoid steel
Eutectoid steel
On decreasing the grain size of a polycrystalline material, the property most likely to deteriorate is
Creep
Toughness
Tensile strength
Fatigue
The __________ of a double acting reciprocating pump as compared to the single acting pump will be almost double.
Flow output
Head developed
Overall efficiency
Weight
The units of the rate constant for a second order reaction are
Pick out the wrong statement.
The equivalent stiffness of two springs (of equal stiffness 'S') in series is S/2 while in parallel is 2S
For a helical spring, deflection is proportional to D3 (D = mean coil diameter) or d4 (d = wire diameter)
Crushing load or columns is less than the buckling load
Modulus of resilience is proportional to (stress at elastic limit)2
Co-efficient of performance of a Carnot cycle refrigerator operating between - 23°C and + 27°C is
3
5
0.5
1.5
The function of neutral flux used in the pyrometallurgy of metal extraction is to increase the __________ of the slag.
Fluidity
Basicity
Acidity
Viscosity