302. The presence of original rounded surface on the manufactured piece of timber, is called
A. Wane
B. Torn grain
C. Diagonal grain
D. Chipmark.

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303.  Pick up the most favourable condition for the rapid growth of fungus for dry rot from the following :
A. absence of sun light
B. dampness
C. presence of sap
D. All the above.

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304. The cracks which extend from bark towards the sap wood in the cross section of a tree, are called
A. radial shakes
B. star shakes
C. heart shakes
D. cup shakes.

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305. The cracks caused by shrinkage of the exterior surface of the wood exposed to atmosphere, are called :
A. radial shakes
B. heart shakes
C. wind cracks
D. twisted fibres.

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306. Pick up the correct statement from the following :
A. The plywoods do not split or crack due to changes in atmosphere
B. The commercial plywoods are available upto 150 cm wide and upto 300 cm long
C. The plywoods possess uniform tensile strength in all directions
D. All the above.

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307. Pick up the correct statement from the following :
A. Alexander Parkes, a Scottish chemist prepared a hard material by mixing camphor and alcohol with nitro cellulose and called it, as Parkesite
B. Dr. L. Bakeland, a Belgian scientist prepared a product known as Bakelite
C. Pollark, an Austrian scientist prepared a substance from urea and formaldehyde and called it Plastic
D. All the above.

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308. Plastics are compounds of carbon with element
A. hydrogen
B. nitrogen
C. oxygen
D. All of these.

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