The pressure outside a bubble/droplet of liquid is __________ the internal pressure.
Greater than
Less than
Equal to
Unpredictable; depends on the bubble size
Correct Answer :
B. Less than
Related Questions
Temperature profile along the length of a gasgas counter flow heat exchanger is correctly represented by
Which one is neutral in character?
N2O4
N2O
N2O5
N2O3
Metal cutting by oxy-acetylene flame is accomplished by the __________ of the metal.
Burning
Intensive oxidation
Evaporation
None of these
Case hardening of a material is
Followed by tempering or carburising
Preceded by its tempering
Done to get a soft ductile interior with a very hard surface
Carried out to get extreme hardness in its core
The joint for soldering is supported by binding wire made of
Mild steel
Copper
Soft iron
Stainless steel
Which of the following is not a ferromagnetic material?
Nickel
Cobalt
Aluminium
Iron
Wrought iron does not have
Uniform strength in all directions
Ability to hold protective coating
High ductility & corrosion resistance
Easily weldable characteristics
All of the following alloying elements of steel increases hardness but sacrifice ductility, except
Nickel
Vanadium
Molybdenum
Chromium
Wood is a/an __________ material.
Amorphous
Cellular
Homogeneous
Granular
Normalising does not __________ of a metal.
Improve machinability & tensile strength
Remove internal stresses
Refine the structure
Remove strains caused by cold working
Triple point of water is
0°F
492°R
0°K
-273°C
Glass reacts with
H2SO3
HF
HNO3
K2Cr2O7
Glycerine is used as a coolant in cooling of some engines instead of water, because
Its higher boiling point (290°C) increases its heat carrying capacity
Comparatively less weight of coolant is required
Smaller radiator can be used
All a, b & c
Flue gases pass through the following boiler accessories in a high pressure natural circulation boiler.
A. Induced draft fan
B. Economiser
C. Air preheater
D. Steam superheater Which of the following gives the correct sequence of flow of the flue gases through the above mentioned boiler accessories?
A, C, B, D
D, B, C, A
D, C, B, A
D, A, B, C
The type of pump used for lifting large quantity of sewage is a __________ pump.
Gear
Centrifugal
Reciprocating
Plunger
Solute atoms which cause yield point phenomenon in mild steel are/is
Aluminium
Boron
Carbon
Nitrogen
Constituents of stellite are
Zinc, copper & nickel
Cobalt, chromium & tungsten
Zinc, aluminium & nickel
Nickel, cobalt & vanadium
Aluminium is extracted from
Chalcocite
Bauxite
Galena
None of these
The highest stress that a material can withstand for a specified length of time without excessive deformation is called the __________ strength.
Creep
Endurance
Fatigue
None of these
Latent heat of dry steam at atmospheric pressure is 539 Kcal/kg; which __________ with increase in the pressure of steam.
Decreases
Increases
Remain same
May increase or decrease
Maraging steels derive their strength from the following mechanism:
A fine, highly dislocated and strong martensite
Fine dispersions of inter-metallic of Fe, Ni, Ti etc
Fine dispersions of alloy carbides in a ferrite matrix
Fine dispersions of 
C nucleated on dislocations in austenite
Use of economiser in a boiler plant reduces the fuel consumption for steam generation by about __________ percent.
1
10
30
50
Removal of non-condensable from steam or other vapour is termed as the __________ process.
Condensation
Deaeration
Scavenging
Exhaust
Parallel straight line pattern of temperature distribution for both hot and cold fluids is observed in case of heat exchanger of the type
Parallel flow with equal heat capacities
Counter flow with equal heat capacities
Counter flow with unequal heat capacities
Parallel flow with unequal heat capacities
Absolute zero, pressure will occur, when the molecular momentum of the system becomes zero. A liquid will cease to exist as liquid at
High vacuum
Zero pressure
0°K
Earth's centre
__________ furnace is generally used in the non-ferrous foundries.
Direct arc
Indirect arc
Resistance
Induction
What is the value of entropy at 273°K?
0
1
∞
None of these
Ceramic compounds as compared to metallic compounds
Crystallise faster
Resist greater tensile stress at room temperature
Have higher melting temperature
Are better conductor of electricity at higher temperature
Super conduction in metals is observed at a temperature of __________ °K.
<100
>100
About 273
About 373
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
The better insulation material should be put just next to pipe (i.e., inside)
The better insulating material should be put outside
Either of the insulating material could be put on either side
Steam temperature is considered before deciding as to which insulating material is to be put inside (i.e., just next to the pipe)