Which of the following is not a dielectric material?
Cotton, silk and paper
Asbestos, glass, porcelain and mica
Rubber and polymeric resins
All refractory materials
Correct Answer :
C. Rubber and polymeric resins
Related Questions
Shampoos are commercially not available in the form of
Powder
Gaseous mixture
Solution
Emulsion
Addition of silicon to cast iron
Promotes graphite module formation
Improves its ductility
Does not promote graphite flakes formation
Increases the fluidity of molten metal
Melting point & boiling points of liquid oxygen are respectively - 218.8°C & - 183°C, while the same for liquid nitrogen is - 210°C & - 195.8°C respectively. The difference in melting points of liquid oxygen & liquid nitrogen is not equal to 8.8
°C
°F
°K
°R
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
Heat transfer by __________ is almost absent in case of fluidised bed drying operation.
Radiation
Conduction
Convection
Both (B) & (C)
Uniform ramming of sand in green sand moulding process leads to
Reduced chance of gas porosity
Greater dimensional stability of the casting
Uniform flow of molten metal into the mould cavity
Less sand expansion type of casting defect
In condensers used in thermal power plants, steam is normally used in shell side and cooling water on the tube side, because of the reason that
Compared to the mass flow rate of cooling water, the rate of condensation of steam is invariably smaller
Maintaining vacuum on tube side is more difficult than that on the shell side
Water velocity can be increased conveniently to increase the overall heat transfer co-efficient because of its lower specific volume compared to steam
Condenser can act as a storage unit for condensed steam
Often earing defects are found during deep drawing operation, because the
Surface finish of the sheet is poor
Sheet material has been given substantial spring back
Starting sheet has planer anisotropy due to its texture
Starting sheet has normal anisotropy due to its texture
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
Which of the following metals is the most prone to work hardening?
Brass
Aluminium
Copper
Lead
The capacity of a spring to store energy is called the spring form co-efficient. Stiffness of a spring is measured by the
Ability to absorb shock
Capacity to store energy
Ratio of the wire & coil diameters
Load to produce unit deflection
The units of the rate constant for a second order reaction are
Two solutions A1 & A2 have pH value of 2 & 6 respectively. It implies that the solution
A1 is more alkaline than solution A2
A1 is highly acidic
A2 is very slightly acidic
Both (B) & (C)
The main charge in blast furnace is usually
Iron ore & coke
Iron ore, coke & air
Limestone, coke & iron ore
Limestone, sand & iron ore
Neutrons are present in all atoms except that of
He
C
H
Ar
For infinite parallel planes having emissivities ε1 & ε2, the interchange factor for radiation from surface 1 to surface 2 is given by
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?
p
2 p
0.5 p
0.25 p
Isotropic materials have the same __________ in all directions.
Induced stresses
Density
Elastic properties
Thermal properties
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
At 100% relative humidity, the dew point temperature of moist air is
Less than the wet bulb temperature
More than the wet bulb temperature
Equal to the wet bulb temperature
Equal to the ambient temperature
__________ circuit is most commonly used to measure strain with the help of a strain gauge.
Ballast
Voltage balancing potentiometric
Simple current sensitive
None of these
What happens, when SO2 is passed through a solution of H2S in water?
Precipitation of sulphur takes place
H2SO3 is formed
Oleum is formed
None of these
Out of the following, the joint produced by __________ has the lowest strength.
Soldering
Welding
Brazing
Riveting
In practice, the compression ratio of compression-ignition (CI) engine ranges from
15 to 25
5 to 10
40 to 55
60 to 70
Mild steel has __________ crystal lattice structure.
Face centred cubic (fcc)
Body centred cubic (bcc)
Orthorhombic
Cubic
Pick out the wrong statement.
The X-rays cannot be deflected by electric field unlike cathode rays
The intensity of X-rays can be measured by ionisation current produced due to the ionisation of gas by X-rays
The quality of X-rays can be controlled by varying the anode-cathode voltage
Crystal structure of a material can be studied by an electron microscope
Metal shots used in shot blasting are made of
Stellite
Steel
Bronze
Lead
Tesla metre per ampere (T. m/A) is the unit for the measurement of
Magnetic susceptibility
Magnetic moment
Permeability of free space
Flux density
Current employed in resistance welding ranges from __________ kVA/
.
1.2 to 2.5
4.5 to 6.2
7.5 to 8.5
10.5 to 15.5
Solute atoms which cause yield point phenomenon in mild steel are/is
Aluminium
Boron
Carbon
Nitrogen