Related Questions

In case of dry spinning of polymers, the polymer solution in a volatile solvent is forced through the spinnerates into a warm air chamber, where the solvent evaporates leaving behind the polymer in the filament form. Dry spinning is used for __________ fibres.
A Polythene
B PVC
C Rayon
D Polyvinyl acetate
In case of wet spinning of polymers, the polymer solution is forced through spinnerates into, a coagulating bath to give a filament form. Wet spinning is not used in case of the __________ fibres.
A Viscose rayon
B Acrylic
C Polyvinyl acetate
D Saturated polyester
For spinning viscose rayon, the extrusion spinnerettes are made of
A Platinum or gold alloys
B High carbon steel
C Aluminium
D Nickel
While the thermosetting polymers are amorphous in nature, the thermoplastic polymers are either amorphous or crystalline. The crystalline polymers are characterised by the
A Low impact strength
B High flexibility
C Better finish and surface appearance
D High plastic deformation
An intrinsic semiconductor has some holes in it at room temperature. What causes these holes?
A Doping
B Valence electrons
C Free electrons
D Thermal energy
E None of the above
In a linear polymer, the monomeric units are linked together to form long straight chains. The cross linked or branched chain polymers compared to linear polymers have higher
A Densities
B Melting point
C Tensile strength
D Hardness, rigidity & brittleness
When the air is passed through an insulated chamber having sprays of water maintained at a temperature higher than the dew point temperature of entering air but lower than its dry bulb temperature, then the air is said to be
A Cooled and humidified
B Cooled and dehumidified
C Heated and humidified
D Heated and dehumidified
Dacron (or terylene) fibres as compared to nylon fibres have
A Better heat & acid resistant properties
B Poorer resistance to alkalis
C Poorer dyeability
D All of the above
Dacron (or terylene) fibres as compared to nylon's fibres have
A Better heat & acid resistant properties
B Poorer resistance to alkalis
C Poorer dyeability
D All of the above
Identify the group in which all the polymers mentioned can be used to make fibres.
A Butadiene copolymers, Polyamides, Urea aldehyde
B Cellulose derivatives, Polyisoprene, Polyethylene
C Cellulose derivatives, Polyamides, Polyurathane
D Polypropylene, Poly vinyl chloride, Silicon

Next steps