Correct Answer:- Option-C

Question75:-Select the correct option
A:-PCTFE is a thermoplastic polymer and its repeating unit is Fcic=cr,
B:-PCTFE is a thermoplastic polymer and its repeating unit is cic=cr,
C:-PCTFE is a thermoplastic polymer and its repeating unit is 7.c=cr,
D:-PCTFE is a thermoplastic polymer and its repeating unit is F:c-cr;
Correct Answer:- Option-A

Question76:-Which of the following statements is true for PVC-O pipes?

A:-PVC-O pipes are obtained by the process of molecular orientation of UPVC
to obtain a layered structure

B:-PVC-O pipes are obtained by turning the layered structure of UPVC into an
amorphous structure

C:-PVC-O pipes are obtained by the addition of modifying agents to PVC
D:-PVC-O pipes are obtained by adding oxygen atoms to PVC
Correct Answer:- Option-A

Question77:-Which of the following will not help in controlling the flow lines in
injection molding?

A:-Increasing the injection speed, pressure and material temperature
B:-Round the corners of the mold where wall thickness increases
C:-Decrease the nozzle diameter to reduce the melt flow rate

D:-Relocation of mold gates to create more distance between them and the
mold coolants

Correct Answer:- Option-C
Question78:-Overhead plastic water tanks are manufactured by process
A:-Injection molding
B:-Rotomolding
C:-Compression molding
D:-Transfer molding
Correct Answer:- Option-B
Question79:-The formation of polyurethane involves chemical reaction between
A:-a di/poly isocyanate and a diol of polyol
B:-Hexamethylene diamine and methanol
C:-Hexamethylene diamine and adipic acid
D:-Terephthalic acid and ethylene glycol
Correct Answer:- Option-A
Question80:-Which of the following statements is correct?

A:-LDPE has low degrees of branching