The radius of a wire is decreased to one-third. If volume remains the same, length will increase?
Correct Answer: 9 times
Explanation:
Let original radius = r and original length = h
New radius = r/3
Let new length = H
Then, π r2h = π (r/3)2 x H = π r2H/9
∴ H = 9h
Thus, the length becomes 9 times .
