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

For doing the experiment it is advisable to use a piece of wood or har

1.	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
Answer» C) When sun rays from a distant object are focused on a sheet of paper, it may start burning