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Maths Quiz for Class 8 Surface Area and Volume |
In this post, we are providing 20 online maths quiz
questions for class 8 surface area and volume. Online maths quiz will take
around 20 minutes to complete it.
Question 1: Which of the following is a unit of volume?
A) cm
B) square cm
C) cubic cm
D) m
Explanation: The unit of the volume is cubic unit. So, cubic cm is a unit of volume.
Question 2: 1 cu. m = _________ cu. cm
A) 1000000
B) 100000
C) 10000
D) 1000
Explanation: 1 cu. m = 100 × 100 × 100 cu. cm = 1000000 cu. cm
Question 3: Find the volume of a cuboid measuring 8 cm by 5 cm by 4 cm.
A) 160 cu. cm
B) 80 cu. cm
C) 40 cu. cm
D) 20 cu. cm
Explanation: Volume of a cuboid = Length × breadth × height = 8 × 5 × 4 = 160 cu. cm
Question 4: Find the volume of a cube whose edge is 12 cm.
A) 144 cu. cm
B) 1728 cu. cm
C) 288 cu. cm
D) 864 cu. cm
Explanation: Volume of a cube = side × side × side = 12 × 12 × 12 = 1728 cu. cm
Question 5: The base diameter of a cylinder is 20 cm and its height is 7 cm. Find the volume of the cylinder.
A) 220 cu. cm
B) 2200 cu. cm
C) 22 cu. cm
D) 22000 cu. cm
Explanation: Radius (r) = Diameter/2 = 20/2 = 10 cm and height (h) = 7 cm. Volume of a cylinder = Ï€r2h = 22/7 × 10 × 10 × 7 = 2200 cu. cm
Question 6: The length of an iron pipe is 84 cm. If its external and internal radii are 10 cm and 7 cm, respectively. Find the volume of iron required to make it.
A) 53,856 cu. cm
B) 13,564 cu. cm
C) 13,464 cu. cm
D) 13,468 cu. cm
Explanation: Volume
of iron required to make the pipe = π(R2
– r2)h = 22/7 ×
(102 – 72) × 84 =
22/7 × (100 – 49) × 84
= 22/7 × 51 × 84
= 22 × 51 × 12
= 13,464 cu. cm
Question 7: Find the volume of a cylinder whose base radius is 14 cm and height 45 cm.
A) 27,740 cu. cm
B) 27,720 cu. cm
C) 27,750 cu. cm
D) 27,780 cu. cm
Explanation: Volume of a cylinder = Ï€r2h = 22/7 × 14 × 14 × 45 = 22 × 2 × 14 × 45 = 27,720 cu. cm
Question 8: Two cylinders have their radii in the ratio 3 : 1 but their heights are in the ratio 1 : 3. Find the ratio of their volumes.
A) 3 : 3
B) 1 : 1
C) 1 : 3
D) 3 : 1
Explanation: Let
the radii of the two cylinders be 3r and r, and their heights be h and 3h,
respectively. Volume of first cylinder = πr2h
= π(3r)2h = 9πr2h. Volume of second cylinder = πr2(3h) = 3πr2h.
Ratio of their volumes = 9Ï€r2h :
3Ï€r2h = 3 : 1
Question 9: The volume of a cube is 729 cu. cm. Find the length of its edge.
A) 9 cm
B) 3 cm
C) 9 cm
D) 27 cm
Explanation: Length
of the edge of a cube = 3√volume
= 3√729
= 3√93
= 9 cm
Question 10: The volume of a cuboid is 560 cu. cm. If length and the breadth of the cuboid are 10 cm and 8 cm, respectively, then find its height.
A) 9 cm
B) 8 cm
C) 7 cm
D) 6 cm
Explanation: Volume of a cuboid = l × b × h => 560 = 10 × 8 × h => 560 = 80h => h = 560/80 => h = 7 cm
Question 11: Find the lateral surface area of a cube whose edge is 8 cm.
A) 384 sq. cm
B) 256 sq. cm
C) 128 sq. cm
D) 512 sq. cm
Explanation: Lateral surface area of a cube = 4l2 = 4 × (8)2 = 4 × 64 = 256 sq. cm
Question 12: Find the total surface area of a cube whose edge is 5 cm.
A) 100 sq.cm
B) 150 sq.cm
C) 200 sq.cm
D) 250 sq.cm
Explanation: Total surface area of a cube = 6l2 = 6 × (5)2 = 6 × 25 = 150 sq. cm
Question 13: Find the lateral surface area of a cuboid measuring 6 cm by 5 cm by 3 cm.
A) 66 sq. cm
B) 126 sq. cm
C) 132 sq. cm
D) 33 sq. cm
Explanation: Lateral surface area of a cuboid = 2 (l + b) h = 2 × (6 + 5) × 3 = 2 × 11 × 3 = 66 sq. cm
Question 14: Find the total surface area of a cuboid measuring 10 cm by 8 cm by 5 cm.
A) 180 sq. cm
B) 680 sq. cm
C) 170 sq. cm
D) 340 sq. cm
Explanation: Total surface area of a cuboid = 2 (lb + bh + lh) = 2 × (10 × 8 + 8 × 5 + 5 × 10) = 2 × (10 × 8 + 8 × 5 + 5 × 10) = 2 × (80 + 40 + 50) = 2 × 170 = 340 sq. cm
Question 15: Find the curved surface area of a cylinder whose base diameter is 14 cm and height is 15 cm.
A) 968 sq. cm
B) 1320 sq. cm
C) 660 sq. cm
D) 330 sq. cm
Explanation: Here, r = 14/2 = 7 cm and h = 15 cm. Curved surface area of a cylinder = 2Ï€rh = 2 × 22/7 × 7 × 15 = 2 × 22 × 15 = 660 sq. cm
Question 16: Find the total surface area of a cylinder whose base radius is 3.5 cm and height is 20 cm.
A) 1034 sq. cm
B) 517 sq. cm
C) 258.5 sq. cm
D) 440 sq. cm
Explanation: Total surface area of a cylinder = 2Ï€r (h + r) = 2 × 22/7 × 3.5 × (20 + 3.5) = 2 × 22 × 0.5 × 23.5 = 22 × 1 × 23.5 = 517 sq. cm
Question 17: Find the total surface area of a hollow cylinder whose external and internal radii are 8 cm and 6 cm, respectively and height is 20 cm.
A) 1936 sq. cm
B) 968 sq. cm
C) 3872 sq. cm
D) 484 sq. cm
Explanation: Here, external radius (R) = 8 cm, internal radius (r) = 6 cm and height (h) = 20 cm. Total surface area of a hollow cylinder = 2Ï€ (R + r) (h + R – r) = 2 × 22/7 × (8 + 6) (20 + 8 – 6) = 2 × 22/7 × 14 × 22 = 2 × 22 × 2 × 22 = 1936 sq. cm
Question 18: The total surface area of a cube is 216 sq. cm. Find the length of its edge.
A) 4 cm
B) 5 cm
C) 6 cm
D) 8 cm
Explanation: Total surface area of a cube = 6l2 => 216 = 6l2 => 216/6 = l2 => 36 = l2 => l2 = 6 × 6 => l = 6 cm
Question 19: Two cylinders have their radii in the ratio 3 : 4 and their heights in the ratio 4 : 3. Find the ratio of their curved surface areas.
A) 3 : 3
B) 1 : 1
C) 4 : 4
D) 3 : 4
Explanation: Let the radii of two cylinders be 3x and 4x. Again, let the heights of the two cylinders be 4y and 3y. Curved surface area of first cylinder = 2Ï€rh = 2 × Ï€ × 3x × 4y = 24Ï€xy sq. units. Curved surface area of second cylinder = 2Ï€rh = 2 × Ï€ × 4x × 3y = 24Ï€xy sq. units. Ratio of their curved surface area = 24Ï€xy/24Ï€xy = 1 : 1
Question 20: A rectangular sheet of paper of dimensions 88 cm × 30 cm is rolled along its length and a cylinder is formed. Find the curved surface area of the cylinder.
A) 264 sq. cm
B) 1320 sq. cm
C) 2640 sq. cm
D) 26400 sq. cm
Explanation: When a rectangular sheet of paper of dimensions 88 cm × 30 cm is rolled along its length and a cylinder is formed, circumference of base = 88 cm and height = 30 cm. Therefore, 2Ï€r = 88 => 2 × 22/7 × r = 88 => 44/7 × r = 88 => r = 88 × 7/44 => r = 14. Curved surface area of a cylinder = 2Ï€rh = 2 × 22/7 × 14 × 30 = 2 × 22 × 2 × 30 = 2640 sq. cm
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