323. Pick up the correct statement from the following :
A. Melamine is obtained from calcium carbide
B. Formaldehyde is prepared synthetically from methane
C. The melamine when reacted with formaldehyde forms the melamine-formaldehyde resin
D. All the above.

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324. Pick up the correct statement from the following :
A. The phenol is carbolic acid
B. The phenol is either extracted from coaltar or prepared from benzene
C. Phenol reacts with formaldehyde, to form phenol formaldehyde resin
D. All the above.

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325. Pick up the correct statement from the following :
A. Catalysts are added to assist and accelerate the hardening of resin,
B. The fillers are inert materials and they impart strength and hardness
C. Fibrous fillers increase thermal resistance
D. All the above.

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326. Pick up the correct statement-from the following :
A. The plastic bottles are made by the-process of blowing
B. The plastic sheets are made by. the calendering process in which the plastic material is'-allowed to pass between cylindrical rollers
C. The application of thermo-setting resins on sheets of paper, is called laminating process
D. All the above.

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327. Pick up the incorrect statement from the following :
A. Plastics are chemical resistant
B. Plastics are durable
C. Plastics are ductile
D. Plastics are excellent electric insulators.

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328. Pick up the non-inflammable plastic from the following:
A. Cellulose acetate plastics
B. Polyvinyl chloride plastics
C. Phenol formaldehyde plastic
D. Urea formaldehyde plastic.

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329. Pick up the correct statement from the following :
A. Plastics have generally low melting point
B. The coefficient of thermal expansion of plastics is about three times than that of steel
C. The acoustical boards prepared by impregnating fibreglass with phenolic resins has absorption coefficient of about 0.67
D. All the above.

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