Solid Figures MCQ Quiz - Objective Question with Answer for Solid Figures - Download Free PDF
Last updated on Jun 9, 2025
Latest Solid Figures MCQ Objective Questions
Solid Figures Question 1:
The combined perimeter of the top and bottom circular faces of a right circular cylinder is 176 cm. The volume of the cylinder is given as 3528π cm³. If the height of the cylinder is three-fourths the length of a side of a square, what is the area of the square (in cm²)?
Answer (Detailed Solution Below)
Solid Figures Question 1 Detailed Solution
Calculation
ATQ, 2 ×(2πr) = 176
Or, 2πr = 88
Or, πr = 44
So, r = 14 cm
Volume of the cylinder = [22/7] r2h = 3528π
So, 196h = 3528
So, h = 18
Side of the square = 18 × [4 / 3] = 24 cm
Required area = 24 × 24 = 576 cm
Solid Figures Question 2:
A 5 m wide cloth is used to make a conical tent of base diameter 14 m and height 24 m. Find the cost of cloth used at the rate of Rs. 25 per metre square. [Use π = 22/7]
Answer (Detailed Solution Below)
Solid Figures Question 2 Detailed Solution
Given:
breadth = 5 m
diameter = 14 m
height = 24 m
Rate = Rs. 25/m
Formula used:
CSA(Cone) = 22/7 x r x l
l2 = h2 + r2
r = radius of the cone/tent(here)
h = slant height
CSA = Curved Surface Area
Solution:
r = 14/2 = 7 m
l = \(\sqrt{24^2 + 7^2} = \sqrt{576 + 49} = \sqrt{625}\)
l = 25 m
CSA = 22/7 x 7 x 25
CSA = 550 m2
Cost of cloth required = 550 x 25 = Rs. 13750
Hence, the correct option is 2.
Solid Figures Question 3:
A solid iron cube of edge 24 cm is melted and recast into a rectangular sheet of thickness 2 mm. If the length (l) and breadth (b) of the sheet are in the ratio 6:5, then l + b (in cm) is
Answer (Detailed Solution Below)
Solid Figures Question 3 Detailed Solution
Given:
Edge of solid iron cube = 24 cm
Thickness of rectangular sheet = 2 mm = 0.2 cm
Ratio of length (l) to breadth (b) = 6:5
Formula Used:
Volume of cube = Volume of rectangular sheet
Volume of cube = Edge3
Volume of rectangular sheet = Length × Breadth × Thickness
l / b = 6 / 5
Calculation:
Volume of cube = Edge3
⇒ Volume = 243
⇒ Volume = 13824 cm3
Volume of rectangular sheet = l × b × 0.2
⇒ 13824 = l × b × 0.2
⇒ l × b = 13824 / 0.2
⇒ l × b = 69120
l / b = 6 / 5
⇒ l = 6k, b = 5k
⇒ l × b = 6k × 5k
⇒ 69120 = 30k2
⇒ k2 = 69120 / 30
⇒ k2 = 2304
⇒ k = √2304
⇒ k = 48
l = 6k = 6 × 48 = 288 cm
b = 5k = 5 × 48 = 240 cm
l + b = 288 + 240
⇒ l + b = 528 cm
The correct answer is option 2 (528 cm).
Solid Figures Question 4:
A solid metallic right circular cylinder of radius 3 inches and height 8 inches is melted and recast into identical hemispheres whose base is equal to the base of the cylinder. Then the number of hemispheres thus formed is
Answer (Detailed Solution Below)
Solid Figures Question 4 Detailed Solution
Given:
Radius of cylinder = 3 inches.
Height of cylinder = 8 inches.
Formula Used:
Volume of cylinder = πr2h
Volume of hemisphere = (2/3)πr3
Calculation:
Volume of cylinder = π × 32 × 8
⇒ Volume of cylinder = π × 9 × 8
⇒ Volume of cylinder = 72π cubic inches
Volume of hemisphere = (2/3)π × 33
⇒ Volume of hemisphere = (2/3)π × 27
⇒ Volume of hemisphere = 18π cubic inches
Number of hemispheres = Volume of cylinder / Volume of hemisphere
⇒ Number of hemispheres = 72π / 18π
⇒ Number of hemispheres = 4
The number of hemispheres formed is 4.
Solid Figures Question 5:
From a wooden cube of edge 14 cm, a right circular cone of maximum volume is carved out. If the volume of the removed portion of the cube is V, then 3 V (in cu.cm) is
Answer (Detailed Solution Below)
Solid Figures Question 5 Detailed Solution
Given:
Edge of the wooden cube = 14 cm.
Formula Used:
Volume of the cube = Edge3
Volume of the cone = (1/3) × π × r2 × h
Maximum volume of the cone when it is carved from a cube: r = h/2, where h = edge of the cube.
Volume of the removed portion = Volume of the cube - Volume of the cone.
Calculation:
Volume of the cube = Edge3
⇒ Volume of the cube = 143
⇒ Volume of the cube = 2744 cm3
Radius (r) of the cone = h / 2 = 14 / 2 = 7 cm
Height (h) of the cone = 14 cm
Volume of the cone = (1/3) × π × r2 × h
⇒ Volume of the cone = (1/3) × 22/7 × 72 × 14
⇒ Volume of the cone = (1/3) × 22 × 49 × 2
⇒ Volume of the cone = (1/3) × 2156
⇒ Volume of the cone = 718.67 cm3
Volume of the removed portion (V) = Volume of the cube - Volume of the cone
⇒ V = 2744 - 718.67
⇒ V = 2025.33 cm3
3V = 3 × 2025.33
⇒ 3V = 6076 cm3
The value of 3V is 6076 cm3.
Top Solid Figures MCQ Objective Questions
A solid hemisphere has radius 21 cm. It is melted to form a cylinder such that the ratio of its curved surface area to total surface area is 2 ∶ 5. What is the radius (in cm) of its base (take π = \(\frac{{22}}{7}\))?
Answer (Detailed Solution Below)
Solid Figures Question 6 Detailed Solution
Download Solution PDFGiven:
The radius of a solid hemisphere is 21 cm.
The ratio of the cylinder's curved surface area to its Total surface area is 2/5.
Formula used:
The curved surface area of the cylinder = 2πRh
The total surface area of cylinder = 2πR(R + h)
The volume of the cylinder = πR2h
The volume of the solid hemisphere = 2/3πr³
(where r is the radius of a solid hemisphere and R is the radius of a cylinder)
Calculations:
According to the question,
CSA/TSA = 2/5
⇒ [2πRh]/[2πR(R + h)] = 2/5
⇒ h/(R + h) = 2/5
⇒ 5h = 2R + 2h
⇒ h = (2/3)R .......(1)
The cylinder's volume and the volume of a solid hemisphere are equal.
⇒ πR2h = (2/3)πr3
⇒ R2 × (2/3)R = (2/3) × (21)3
⇒ R3 = (21)3
⇒ R = 21 cm
∴ The radius (in cm) of its base is 21 cm.
The surface area of three faces of a cuboid sharing a vertex are 20 m2, 32 m2 and 40 m2. What is the volume of the cuboid?
Answer (Detailed Solution Below)
Solid Figures Question 7 Detailed Solution
Download Solution PDFThe surface area of three faces of a cuboid sharing a vertex are 20 m2, 32 m2 and 40 m2,
⇒ L × B = 20 sq. Mt
⇒ B × H = 32 sq. Mt
⇒ L × H = 40 sq. Mt
⇒ L × B × B × H × L × H = 20 × 32 × 40
⇒ L2B2H2 = 25600
⇒ LBH = 160
∴ Volume = LBH = 160 m3A solid cube of side 8 cm is dropped into a rectangular container of length 16 cm, breadth 8 cm and height 15 cm which is partly filled with water. If the cube is completely submerged, then the rise of water level (in cm) is:
Answer (Detailed Solution Below)
Solid Figures Question 8 Detailed Solution
Download Solution PDFGiven:
Each side of the cube = 8 cm
The rectangular container has a length of 16 cm, breadth of 8 cm, and height of 15 cm
Formula used:
The volume of cube = (Edge)3
The volume of a cuboid = Length × Breadth × Height
Calculation:
The volume of cube = The volume of the rectangular container with a length of 16 cm, breadth of 8 cm, and height of the water level rise
Let, the height of the water level will rise = x cm
So, 83 = 16 × 8 × x
⇒ 512 = 128 × x
⇒ x = 512/128 = 4
∴ The rise of water level (in cm) is 4 cm
The sum of length, breadth and height of a cuboid is 21 cm and the length of its diagonal is 13 cm. Then the total surface area of the cuboid is
Answer (Detailed Solution Below)
Solid Figures Question 9 Detailed Solution
Download Solution PDFGiven:
Sum of length,, breadth and height of a cuboid = 21 cm
Length of the diagonal(d) = 13 cm
Formula used:
d2 = l2 + b2 + h2
T.S.A of cuboid = 2(lb + hb +lh)
Calculation:
⇒ l2 + b2 + h2 = 132 = 169
According to question,
⇒ (l + b + h)2 = 441
⇒ l2 + b2 + h2 + 2(lb + hb +lh) = 441
⇒ 2(lb + hb +lh) = 441 - 169 = 272
∴ The answer is 272 cm2 .
Three cubes with sides in the ratio of 3 ∶ 4 ∶ 5 are melted to form a single cube whose diagonal is 18√3 cm. The sides of the three cubes are:
Answer (Detailed Solution Below)
Solid Figures Question 10 Detailed Solution
Download Solution PDFGiven:
Three cubes with sides in the ratio of 3 ∶ 4 ∶ 5 are melted to form a single cube whose diagonal is 18√3 cm.
Concept used:
The diagonal of a cube = √3a (where a is the sides)
Calculation:
Let the s sides of the cubes will be 3x cm , 4x cm, and 5x cm
As per the question,
Volume of the new cube is
(3x)3 +( 4x)3 +( 5x)3 = 216 x3.
⇒ side is = 6x
diagonal is 6x√3
⇒ 6x√3 = 18√3
⇒ x = 3
The sides of the cubes will be 9 cm , 12 cm, and 15 cm
∴ The correct option is 2
If the surface area of a sphere is 1386 cm2, then find the radius of the sphere.
Answer (Detailed Solution Below)
Solid Figures Question 11 Detailed Solution
Download Solution PDFGIVEN:
The surface area of a sphere = 1386 \(cm^2\)
FORMULA USED:
The surface area of a sphere = 4πr2where r is the radius of the sphere.
CALCULATION:
The surface area of a sphere =4πr2 = 1386
⇒ 4 × (22/7) × r2 = 1386 ....(value of \(\pi\) is \(\frac{22}{7}\))
⇒ r2 = 110.25
⇒ r2 = \(\frac{11025}{100}\)
⇒ r = \(\sqrt\frac{11025}{100}\) = \(\frac{105}{10}\) = 10.5 cm.
∴ The radius of the sphere is 10.5 cm.
A solid cone with curved surface area twice its base area has slant height of 6√3 cm. Its height is:
Answer (Detailed Solution Below)
Solid Figures Question 12 Detailed Solution
Download Solution PDFGiven:
The curved surface area of the cone = 2 × base area of cone
Concepts used:
Formula used
Slant height (l) of cone = √r2 + h2
CSA of cone = πrl
Calculation:
Let the radius of the cone be r units.
⇒ πrl = 2πr2
⇒ l = 2r
⇒ r = 6√3/2
⇒ r = 3√3
Slant height (l) of cone = √r2 + h2
⇒ 6√32 = 3√32 + h2
⇒ h2 = 108 - 27 = 81
⇒ h = 9 cm
∴ The answer is 9 cm.
To pack a set of books, Gautam got cartons of a certain height that were 48 inches long and 27 inches wide. If the volume of such a carton was 22.5 cubic feet, what was the height of each carton? [Use 1 foot = 12 inches.]
Answer (Detailed Solution Below)
Solid Figures Question 13 Detailed Solution
Download Solution PDFGIVEN:
Cartons having length = 48 inches and breadth = 27 inches
The volume of cartoon = 22.5 cubic feet.
FORMULA USED :
Volume of Cuboid = Length × Breadth × Height
CALCULATION :
Volume of carton = volume of cuboid = Length × Breadth × Height
⇒ volume of carton = 48 × 27 × Height
∵ 1 foot = 12 inches, then 22.5 cubic feet = 22.5 × 12 × 12 ×12
⇒ 22.5 × 12 × 12 × 12 = 48 × 27 × Height
⇒ 38,880 = 1,296 × Height
⇒ Height = 30 inches.
∴ The height of each cartoon is 30 inches.
A sphere of radius 42 cm is melted and recast into a cylindrical wire of radius 21 cm. Find the length of the wire.
Answer (Detailed Solution Below)
Solid Figures Question 14 Detailed Solution
Download Solution PDFGiven:
Radius of Sphere = 42 cm
Radius of wire = 21 cm
Formula:
Volume of cylinder = πr2h
Volume of sphere = [4/3]πr3
Calculation:
Let length of the wire be x, then
According to the question
π × 21 × 21 × x = [4/3] × π × 42 × 42 × 42 [As volume will remain constant]
⇒ x = (4 × 42 × 42 × 42)/(21 × 21 × 3)
⇒ x = 224 cm
∴ The length of the wire is 224 cm
A spherical metal of radius 10 cm is molten and made into 1000 smaller spheres of equal sizes. In this process the surface area of the metal is increased by:
Answer (Detailed Solution Below)
Solid Figures Question 15 Detailed Solution
Download Solution PDFFormula Used:
Volume of sphere = \(\frac{4}{3}\)πr3
Surface area of sphere = 4πr2
Calculation:
If the radius of a smaller sphere be 'r cm' then
Acoording to the question:
\(\frac{4}{3}\)π(10)3 = 1000\(\frac{4}{3}\)π(r)3
r = 1 cm
Surface area of the larger sphere = 4π(10)2 = 400π
Total surface area of 1000 smaller spheres = 1000 × 4π(1)2 = 4000π
Net increase in the surface area = 4000π − 400π = 3600π
Hence, surface area of the metal is increased by 9 times.