Right Circular Cylinder
Multiple Choice Questions (MCQ)
- What is the formula for the curved surface area (CSA) of a right circular cylinder?
A. πr²h
B. 2πrh
C. 2πr(h + r)
D. πrh²
Answer: B. 2πrh - If the radius of a cylinder is 3 cm and the height is 7 cm, what is its volume?
A. 198 cm³
B. 132 cm³
C. 154 cm³
D. 66 cm³
Answer: A. 198 cm³
(V = πr²h = 22/7 × 3² × 7 = 198 cm³) - The total surface area (TSA) of a cylinder includes:
A. Only one circular base and side surface
B. Two circular bases only
C. Side surface and both circular bases
D. Only the side surface
Answer: C. Side surface and both circular bases - Which of the following is not a real-life example of a right circular cylinder?
A. Water tank
B. Tin can
C. Cubical box
D. Pipe
Answer: C. Cubical box - If CSA = 440 cm² and height = 10 cm, then what is the radius of the cylinder?
A. 7 cm
B. 6 cm
C. 5 cm
D. 8 cm
Answer: A. 7 cm
(CSA = 2πrh ⇒ 440 = 2 × 22/7 × r × 10 ⇒ r = 7)
Short Answer Questions (SAQ)
- Write the formula for the volume of a right circular cylinder.
Answer: Volume = πr²h - A cylinder has a height of 14 cm and radius of 7 cm. What is its total surface area (TSA)?
Answer: Total surface area = 2πr(h + r)
= 2 × 22/7 × 7 × (14 + 7) = 924 cm² - Mention one difference between curved surface area (CSA) and total surface area (TSA).
Answer: Curved surface area includes only the lateral/side surface, while total surface area includes curved surface area plus both circular bases.
Long Answer Questions (LAQ)
1.A cylindrical tank has radius 5 cm and height 10 cm.
(a) Find the curved surface area (CSA)
(b) Find the total surface area (TSA)
(c) State which formulae you used
Answer: (a) CSA = 2πrh = 2 × 22/7 × 5 × 10 = 314.29 cm²
(b) TSA = 2πr(h + r) = 2 × 22/7 × 5 × (10 + 5) = 471.43 cm²
(c) Used formulae: CSA = 2πrh and TSA = 2πr(h + r)
2.The volume of a right circular cylinder is 616 cm³ and the radius is 4 cm.
(a) Find the height of the cylinder.
(b) Write the formula used.
(c) Give one real-life application of this calculation.
Answer: (a) Volume = πr²h
⇒ 616 = 22/7 × 4² × h ⇒ 616 = 22/7 × 16 × h
⇒ h = (616 × 7) / (22 × 16) = 12.25 cm
(b) Formula used: Volume = πr²h
(c) Real-life use: To calculate the water storage capacity of a tank.