Advertisements
Advertisements
Question
The curved surface area of a cylinder is reduced by ______ per cent if the height is half of the original height.
Solution
The curved surface area of a cylinder is reduced by 50 per cent if the height is half of the original height.
Explanation:
The curved surface area of a cylinder with radius r and height h = 2πrh
If the height is halved, then new curved surface area of cylinder = `2pir h/2 = pirh`
∴ Percentage reduction in curved surface area = `(2pirh - pirh)/(2pirh) xx 100`
= `(pirh)/(2pirh) xx 100`
= 50%
APPEARS IN
RELATED QUESTIONS
It is required to make a closed cylindrical tank of height 1 m and base diameter 140 cm from a metal sheet. How many square meters of the sheet are required for the same?
The height of a right circular cylinder is 10.5 m. Three times the sum of the areas of its two circular faces is twice the area of the curved surface. Find the volume of the cylinder.
A rectangular sheet of paper 30 cm × 18 cm can be transformed into the curved surface of a right circular cylinder in two ways i.e., either by rolling the paper along its length or by rolling it along its breadth. Find the ratio of the volumes of the two cylinders thus formed.
Find the cost of sinking a tubewell 280 m deep, having diameter 3 m at the rate of Rs 3.60 per cubic metre. Find also the cost of cementing its inner curved surface at Rs 2.50 per square metre.
If r is the radius and h is height of the cylinder the volume will be
A right circular cylindrical tunnel of diameter 2 m and length 40 m is to be constructed from a sheet of iron. The area of the iron sheet required in m2, is
Radius of base of a cylinder is 20 cm and its height is 13 cm, find its curved surface area and total surface area. (π = 3.14)
The dimensions of a car petrol tank are 50 cm × 32 cm × 24 cm, which is full of petrol. If a car's average consumption is 15 km per liter, find the maximum distance that can be covered by the car.
The radius and height of a cylinder are in the ratio 5:7 and its curved surface area is 5500 sq.cm. Find its radius and height.
The surface area of a cylinder which exactly fits in a cube of side b is ______.
