# NCERT Mathematics Class 9 Exemplar Ch 13 Surface Areas and Volumes Part 5 (For CBSE, ICSE, IAS, NET, NRA 2022)

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**Exercise 13.4**

Q. 1. A cylindrical tube opened at both the ends is made of iron sheet which is thick. If the outer diameter is and its length is , find how many cubic centimeters of iron has been used in making the tube?

Answer:

Q. 2. A semi-circular sheet of metal of diameter is bent to form an open conical cup. Find the capacity of the cup.

Answer:

Q. 3. A cloth having an area of is shaped into the form of a conical tent of radius 5 m

(i) How many students can sit in the tent if a student, on an average, occupies on the ground?

(ii) Find the volume of the cone.

Answer:

Q. 4. The water for a factory is stored in a hemispherical tank whose internal diameter is . The tank contains 50 kiloliters of water. Water is pumped into the tank to fill to its capacity. Calculate the volume of water pumped into the tank.

Answer:

Q. 5. The volumes of the two spheres are in the ratio . Find the ratio of their surface areas.

Answer:

Q. 6. A cube of side 4 cm contains a sphere touching its sides. Find the volume of the gap in between.

Answer:

Q. 7. A sphere and a right circular cylinder of the same radius have equal volumes. By what percentage does the diameter of the cylinder exceed its height?

Answer:

Q. 8.30 circular plates, each of radius and thickness 3cm are placed one above another to form a cylindrical solid. Find:

(i) The total surface area

(ii) Volume of the cylinder so formed.

Answer: (i) (ii)