Volume of hollow hemispherical shell of radii R and r is equal to
2/3πr3
4/3πR3
2/3π(R3-r3)
4/3π(R3-r3)
A cone of height 15cm and base diameter 30cm is curved onto a wooden sphere of radius 15cm. Then the percentage of wasted wood is
50%
75%
40%
25%
Volumes of two spheres are in the ratio 64:27. The ratio of their surface area is
3:4
4:3
9:16
16:9
If radius of a sphere is doubled then its volume becomes ---- times.
1
2
4
8
Spherical ball of diameter 21cm is melted and recasted into cubes, each of side 1cm. Find the numbers of cubes thus formed.
4800
5800
4851
5851
A solid sphere of radius 3cm is melted and then recast into small spherical balls each of diameter 0.6cm. Find the number of small balls thus obtained.
250
1000
1200
1500
The depth of a bucket is 42cm and the diameter if its top and bottom are 30cm and 10cm respectively. Then, the volume of the bucket is
14,400 cm3
14,100 cm3
14,200 cm3
14,300 cm3
The diameter of a copper sphere is 6cm. The sphere is melted and is drawn into a long wire of uniform circular cross-section. If the length of the wire is 36cm, find its radius.
1cm
1.5cm
2cm
3cm
A spherical ball of lead 3 cm in diameter, is melted and recast into three spherical balls. The diameter of two of these balls are 1.5 cm and 2 cm respectively. Then, the diameter of the third ball is
3 cm
2.5 cm
2.6 cm
3.5 cm
The diameter of a garden roller is 1.4m and it is 2m long. How much area will it cover in 5 revolutions? (Take Π=22/7)
44 m2
40 m2
22 m2
14 m2
