[CLASS 9] Maths MCQs on Volume of a Cylinder and Answers

Mathematics Multiple Choice Questions on “Volume of a Cylinder”.

1. Volume of a cylinder having radius r and height h is given by __________
a) r * h²
b) h * r²
c) πr²h
d) (frac{1}{3})πr²h

Answer: c
Clarification: Volume of a cylinder can be given by multiplying base area with its height.
Hence, volume of a cylinder having radius r and height h is equal to πr²h where πr² is base area and h is height.

2. A cylinder has radius of 7cm and its volume is 1540cm³, what is the height of the cylinder? (Take π = (frac{22}{7}))
a) 10cm
b) 14cm
c) 11cm
d) 15cm

Answer: a
Clarification: Volume of a cylinder having radius r and height h is equal to πr²h.
πr²h = 1540
(frac{22}{7}) * 7 * 7 * h = 1540
h = 10cm.

3. A cylinder has volume of 176cm³ and height equal to 14cm, what is the diameter of the cylinder? (Take π = (frac{22}{7}))
a) 6cm
b) 8cm
c) 2cm
d) 4cm

Answer: d
Clarification: Volume of a cylinder having radius r and height h is equal to πr²h.
πr²h = 176
(frac{22}{7}) * 14 * r² = 176
r² = 4
Therefore, r = 2cm
We know that diameter = 2 * radius
= 2 * 2
= 4cm.

4. A glass of cylindrical shape has radius of 3.5cm and height equal to 8cm. A water jug has a volume equal to 1540cm³. How many times the water has to be poured from glass to fill the jug completely? (Take π = (frac{22}{7}))
a) 6
b) 5
c) 4.5
d) 4

Answer: b
Clarification: Volume of a cylindrical glass = πr²h
= (frac{22}{7}) * 3.5 * 3.5 * 8
= 308cm³
Volume of a water jug = 1540cm³
Therefore, number of times the water has to be poured from glass to fill the jug completely
= (frac{Volume ,of ,a ,water ,jug}{Volume ,of ,a ,cylindrical ,glass} = frac{1540}{308})
= 5.

5. Cylindrical pillars are to be made for a flat whose radius is 15cm and height is 3.5m. What is the total amount of concrete (in cm³) required to make 15 identical pillars? (Take π = (frac{22}{7}))
a) 3513600
b) 3712500
c) 4125300
d) 3917800

Answer: b
Clarification: Volume of one cylindrical pillar = πr²h
= (frac{22}{7}) * 15 * 15 * 350
= 247500cm³
Hence, total volume of 15 pillars = 15 * 247500
= 3712500cm³
Therefore, the total amount of concrete required to make 15 identical pillars = 3712500cm³.

6. A cylinder has a base area equal to 21cm² and height equal to 11cm. What is the volume of the cylinder? (Take π = (frac{22}{7}))
a) 230cm³
b) 220cm³
c) 225cm³
d) 231cm³

Answer: d
Clarification: We know that base area of a cylinder is equal to πr².
Volume of a cylinder = πr²h
= 21 * 11
= 231cm³.

7. A steel pipe has outer radius equal to 3cm and inner radius equal to 2cm. Its length is equal to 5m. What is the mass of the pipe if one cm³ of steel is 8.05 gram? (Take π = (frac{22}{7}))
a) 63.25 kg
b) 65 kg
c) 67 kg
d) 61 kg

Answer: a
Clarification: Let the outer radius = r_o = 3cm
Inner radius = r_i = 2cm
Height (here length) = l = 5m = 500cm
Volume of pipe = π * (r_o² – r_i²) * l
= (frac{22}{7}) * (3² – 2²) * 500
= 7857.14cm³
Mass of 1cm³ is 8.05 gram
Therefore, mass of 7857.14cm³ is equal to 8.05 * 7857.14
= 63249.97gm
≈ 63250 gm
= 63.25 kg.