For doing the experiment it is advisable to use a piece of wood or hard cardboard in the place of paper. Because 

A) Paper is costlier 

B) White sheet of paper is not easily available 

C) When sun rays from a distant object are focused on a sheet of paper, it may start burning 

D) None of the above reasons

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1 Answers

C) When sun rays from a distant object are focused on a sheet of paper, it may start burning

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