Neutrons are present in all atoms except that of
He
C
H
Ar
Correct Answer :
C. H
Related Questions
The behaviour of a metal specimen, which when plastically strained in tension reduces its yield stress in compression and vice versa; is termed as the
Work hardening
Bauschinger effect
Creeping effect
Stress recovery effect
Venturimeter is used to measure the flow rate of fluids in pipes, when the pipe is in __________ position.
Horizontal
Vertical
Inclined
Any
Steel is welded using the __________ flame.
Carburising
Neutral
Oxidising
All (A), (B) & (C)
The best lubricants for a machine working at high temperature & load is
Grease
Solid lubricant
Animal oils
Mineral oils
The cooling rate required to freeze 1 ton of water at 0°C into ice at 0°C in 24 hours is __________ BTU/hr.
100
200
1000
2000
Which of the following metals is not subjected to electrolytic refining/purification?
Copper
Zinc
Tin
Aluminium
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
∞
The minimum carbon content in steel should be __________ percent for it to respond to a hardening treatment.
0.2
0.4
0.6
0.8
A fluid is termed as the Newtonian fluid, when the shear stress is __________ the velocity gradient.
Independent of
Inversely proportional to
Directly proportional to
None of these
Dryness fraction of dry steam is
0
∞
1
0.5
Thermit welding uses the following energy source.
Electrical energy
Chemical energy
Energy of high velocity electrons
Heat generated by friction
Shrinkage allowance on pattern is provided to compensate for shrinkage when the
Metal changes from liquid state to solid state at freezing temperature
Solid phase temperature drops from freezing temperature to the room temperature
Liquid metal temperature drops from pouring temperature to room temperature
Liquid metal temperature drops from pouring temperature to freezing temperature
The boiling & freezing points on a newly defined temperature scale in degree 'D' are 400°D & 100°D respectively. The temperature reading corresponding to 60°C on this new temperature scale will be equal to __________ °D.
140
180
240
280
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 ratio of the shear stress to the principal stress on a principal plane is
0
1
1/2
1/3
Air/fuel ratio on molar (volume) basis for combustion of methane with theoretical quantity of air with be
9.5 : 1
12.5 : 1
15.5 : 1
18.5 : 1
Exposure to __________ accelerates the degradation of plastics.
Ultraviolet radiation
High atmospheric temperature
High ambient temperature
Damp atmosphere
Electrochemical corrosion can occur, only if __________ is present in contact with metal.
Air
Oxygen
Liquid medium
Gaseous medium
Hot & cold working of material causes its __________ deformation.
Visco-elastic
Isotropic
Elastic
Plastic
Spherical shape of mercury droplets is due to its
High viscosity
Low surface tension
High density
High surface tension
Which of the following is the largest quantum of pressure?
1 kg/cm2
1 bar
1 atmosphere
1 kilo Pascal
Carnot cycle is also termed as the constant __________ cycle in thermodynamics.
Entropy
Pressure
Volume
Heat
Which of the following are considered applications of ultrasonic testing?
Determination of elastic constant
Detection of defects in metal
Measurement of material thickness
None of the above
Dry saturated steam can be converted into superheated steam by
Increasing its cross-sectional area of flow
Passing it through a pressure reducing valve
Forcing it downwards through a vertical tube
None of these
A cylindrical rod subjected to a tensile strain within the elastic limit undergoes a volume change. If the volume strain is equal to half the tensile strain, then the Poisson's ratio of the rod is
0
0.33
0.44
0.25
Between 230 and 370°C, blue brittleness is caused in mild steel because of the
Immobility of dislocation
Strain-ageing
Increase in Young's modulus
Strain hardening
The most abundant metal present in the earth's crust is;
Iron
Copper
Titanium
Aluminium
Satellites burn off during re-entry to earth's atmosphere, because of the
Combustion with air
Gravitational pull by earth
Friction with earth's atmosphere
Loss in weight of the satellite
Other parameters remaining same, the recrystallisation temperature of an alloy is lowered, when
Strain rate is increased
Grain size is increased
Prior cold deformation is increased
Not affected by any of the above parameters
If Reynolds number is greater than 1, then the
Viscous force is larger than the inertia force
Inertia force is larger than the viscous force
Inertia force is larger than the surface tension force
Inertia force is larger than the gravitational force