The pillars of a temple are cylindrically shaped (see Fig. 13.26). If each pillar has a circular base of radius 20 cm and height 10 m, how much concrete mixture would be required to build 14 such pillars?

A baby powder tin has square base with side 9 cm and height 12 cm. Another has circular base with radius 3.5 cm and height 10 cm. Which of the two contains more powder and by how much ?

The students of a Vidyalaya were asked to participate in a competition for making and decorating penholders in the shape of a cylinder with a base, using cardboard. Each penholder was to be of radius 3 cm and height 10.5 cm. The Vidyalaya was to supply the competitors with cardborad. If there were 35 competitors, how much cardboard was required to be bought for the competiton ?

The students of a Vidyalaya were asked to participate in a competition for making and decorating penholders in the shape of a cylinder with a base, using cardboard. Each penholder was to be of radius 3 cm and height 10.5 cm. The Vidyalaya was to supply the competitors with cardboard. If there were 35 competitors, how much cardboard was required to be bought for the competition?Assume pi = 22/7 , unless stated otherwise.

A soft drink is available in two packs – (i) a tin can with a rectangular base of length 5 cm and width 4 cm, having a height of 15 cm and (ii) a plastic cylinder with circular base of diameter 7 cm and height 10 cm. Which container has greater capacity and by how much? Assume pi = 22/7 , unless stated otherwise.

In a building there are 24 cylindrical pillars. The radius of each pillar is 28 cm and height is 4 m. Find the total cost of painting the curved surface area of all pillars at the rate of Rs 8 per m^2 .

It is required to make from a sheet of metal a closed cylindrical tank whose height is 1 m and whose base radius is 70 cm. How many square metres of sheet metal is required ?

An open metal bucket is in the shape of a frustum of a cone, mounted on a hollow cylindrical base made of the same metallic sheet (see Fig. 13.23). The diameters of die two circular ends of the bucket are 45 cm and 25 cm, the total vertical height of the bucket is 40 cm and that of the cylindrical base is 6 cm. Find the area of the metallic sheet used to make the bucket, where we do not take into account the handle of the bucket. Also, Find the volume of water the bucket can hold. (Take pi=22/7 ).

Consider a 20 W bulb emitting light of wavelength 5000 oversetcircA and shining on a metal surface kept at a distance 2m . Assume that the metal surface work function of 2eV and that each atom on the metal surface can be treated as a cirular disc of radius 1.5 A. How much time would be required by the atomic disc to receive enrgy equal to work function.