A cylinder of radius and height both equal to 10 cm. made by paper is unfolded to form a plane sheet

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12 Mar 2014 Solve

A cylinder of radius and height both equal to 10 cm. made by paper is unfolded to form a plane sheet of paper. If circumference of a circle is 2*Pi*R, then area of plane paper sheet is-

OPtion

1) 100 Pi
2) 400 Pi
3) 300 Pi
4) 200 Pi
5) 20 Pi
6) 10 Pi
7) 40 Pi
8) 2 Pi
9) 5 Pi
10)None of these

Solution

When we unfold a cylinder, its height becomes breadth of paper and circumference becomes length of paper,
therefore area is l×2*Pi*R = 10×2*Pi*10 = 200*Pi

Correct Option: 4 Best Solution (0)