Multiple Choice Questions
Q1: Surface area of bowl of radius r cm is
(a) 4πr2
(b) 2πr2
(c) 3πr2
(d) πr2
Q2: A conical tent is 10 m high and the radius of its base is 24 m then slant height of the tent is
(a) 26
(b) 27
(c) 28
(d) 29
Q3: Diameter of the base of a cone is 10.5 cm and its slant height is 10 cm . then curved surface area.
(a) 155 cm2
(b) 165 cm2
(c) 150 cm2
(d) None of these
Q4: The surface area of a sphere of radius 5.6 cm is
(a) 96.8π cm2
(b) 94.08π cm2
(c) 90.08π cm2
(d) None of these
Q5: The height and the slant height of a coneare 21 cm and 28 cm respectively then volume of cone
(a) 7556 cm3
(b) 7646 cm3
(c) 7546 cm3
(d) None of these
Fill in the blank
Q1: Surface area of sphere of diameter 14cm is____________.
Q2: Volume of hollow cylinder is ______________.
Q3: Find the volume of a sphere whose surface area 154cm2 is_________________.
Q4: A hemispherical bowl has a radius of 3.5cm. What would be the volume of water it would contain__________.
Q5: The formula for the volume of a cone is __________.
True / False
Q1: The volume of a sphere is equal to two-third of the volume of a cylinder whose height and diameter are equal to the diameter of the sphere.
Q2: If the radius of a right circular cone is halved and height is doubled, the volume will remain unchanged.
Q3: If the radius of a cylinder is doubled and its curved surface area is not changed, the height must be halved.
Q4: Doubling the radius of a sphere will double its volume.
Q5: The total surface area of a cone is the sum of its lateral surface area and the area of its circular base.
Subjective Type Questions
Q1: Diameter of the base of a cone is 10.5 cm and its slant height is 10 cm . Find its curved surface area and its total surface area.
Q2: A Joker’s cap is in the form of a right circular cone of base radius 7 cm and height 24 cm. Find the area of the sheet required to make 10 such caps.
Q3: Find the surface area of a sphere of diameter:
(i) 14cm
(ii) 21cm
(iii) 3.5cm
Q4: A hemispherical bowl is made of steel, 0.25cm thick. The inner radius of the bowl is 5cm . Find the outer curved surface area of the bowl.
Q5: Twenty-seven solid iron spheres, each of radius r and surface area S are melted to form a sphere with surface area S ‘. Find the:
(i) radius r ‘ of the new sphere.
(ii) ratio of S and S ‘.
Q6: A capsule of medicine is in the shape of a sphere of diameter 3.5mm . How much medicine (in mm3) is needed to fill this capsule?