Tag: volume of cylinder

Questions Related to volume of cylinder

Multiple choice maths area and volume of cylinder hollow cylinder volume of cylinder volume of cylinder and cone

The circumference of base of cylindrical reservoir is $\displaystyle 30\pi cm$ and height is $10$ cm. How many litres of water can it hold?

  1. $\displaystyle 2.1\pi$ litres
  2. $\displaystyle 2.25\pi$ litres
  3. $\displaystyle 225\pi$ litres
  4. $\displaystyle 2250\pi$ litres
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Circumference $\displaystyle 2\pi r=30\pi ,r=\frac { 30\pi  }{ 2\pi  } =15$

Volume of cylinder $\displaystyle =\pi { r }^{ 2 }h$

$\displaystyle =\left( \pi \times 10\times 15\times 15 \right) { cm }^{ 3 }$

$\displaystyle =2250\pi { cm }^{ 3 }$

$\displaystyle =2.25\pi l$

Multiple choice maths area and volume of cylinder hollow cylinder volume of cylinder volume of cylinder and cone

The inner diameter of a circular well is $3.5$ m. It is $10$ m deep. Find the cost of plastering this curved surface at the rate of Rs. $40$ per m$^2$.

  1. Rs. $4000$
  2. Rs. $4400$
  3. Rs. $4500$
  4. Rs. $4800$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Given diameter of well is $3.5$ m and depth is $10$ m and cost of plastering is Rs. $40$ per sq m.

Then radius of well $=\dfrac{3.5}{2}=1.75$ m
And height of well $=10$ m
Then curved surface area of well $=$ $2\pi rh=2\times \dfrac{22}{7}\times 1.75\times 10$
$=$ $2\times 22\times 0.25\times 10=110 m^{2}$
Then cost of plastering curved surface area $=$ $110\times 40=$ Rs. $4400$.

Multiple choice maths area and volume of cylinder hollow cylinder volume of cylinder volume of cylinder and cone

The height of a hollow cylinder is $7 cm$ and its radius is $3.5 cm$. Then the surface area is

  1. $231{ cm }^{ 2 }$
  2. $154{ cm }^{ 2 }$
  3. $308{ cm }^{ 2 }$
  4. $115.5{ cm }^{ 2 }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Given : radius $r=3.5 cm$ and height $h=7cm$

Surface area of a hollow cylinder $=2\pi r(h+r)$
                                                        $=2\times 3.14\times 3.5(7+3.5)$
                                                        $=230.79cm^2\approx 231$
$\therefore$ Surface area $=231cm^2$.

Multiple choice maths area and volume of cylinder hollow cylinder volume of cylinder volume of cylinder and cone

A magnet is in the form of a ring with inner diameter $4cm$ and outer diameter $6cm$. If the thickness of the magnet is $2cm$ . What is the cost of fabricating the surface of the magnet if the cost of fabrication per ${cm}^{2}$ is $Rs.10$

  1. $Rs.950$
  2. $Rs.945$
  3. $Rs.942$
  4. $Rs.1000$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Surface area of a ring-shaped magnet (hollow cylinder) includes inner CSA, outer CSA, and two annular ends. Inner r=2, outer R=3, h=2. Area = 2*pi*r*h + 2*pi*R*h + 2*(pi*R^2 - pi*r^2) = 2*pi*2*2 + 2*pi*3*2 + 2*pi*(9-4) = 8*pi + 12*pi + 10*pi = 30*pi. 30 * 3.14 = 94.2. Cost = 94.2 * 10 = 942.

Multiple choice maths area and volume of cylinder hollow cylinder volume of cylinder volume of cylinder and cone

A flower pot is in the form of a hollow cylinder with a closed base with inner radius $2cm$ and outer radius $4cm$ . The height of the flower pot is $10cm$ . If the pot has to be polished find the cost of polishing if the cost of polishing per ${cm}^{2}$ is $Rs.2$.

  1. $Rs.276.32$
  2. $Rs.275$
  3. $Rs.270$
  4. $Rs.278.64$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

We have to first find the total surface area of the flower pot.
Outer radius $=4cm$
Inner radius $=2cm$
Height of flower pot $=10cm$
Total surface area $=A=2\pi Rh+2\pi rh+\pi { { R }^{ 2 } }+\pi { { r }^{ 2 } }$
$A=2\pi (R+r)h+\pi ({ R }^{ 2 }+{ r }^{ 2 })\ A=2\pi (4+2)2+\pi (16+4)\ A=24\pi +20\pi =44\pi \ A=40\pi =44\times 3.14=138.16{ cm }^{ 2 }$
Cost of fabrication per ${cm}^{2}$ $=Rs.2$
Total cost of fabrication $==138.16\times 2=Rs.276.32$

Multiple choice maths area and volume of cylinder hollow cylinder volume of cylinder volume of cylinder and cone

What will be the Inner surface area of a spherical shell of inner radius $15\ cm$ and outer radius $16\ cm$? (Correct upto 2 decimal places)

  1. $706.86\ {cm^2}$
  2. $804.25\ {cm^2}$
  3. $2827.43\ {cm^2}$
  4. $3216.99\ {cm^2}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Inner surface area of a spherical shell = 4 * pi * r^2. With r = 15, Area = 4 * 3.14159 * 225 = 2827.43 cm^2.

Multiple choice maths area and volume of cylinder hollow cylinder volume of cylinder volume of cylinder and cone

The surface area of a solid sphere is always greater than the surface area of a hemisphere for the same value of radius.

  1. True

  2. False

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Let radius of solid sphere=radius of hemisphere$=r$
Then, S.A of solid sphere$=4\pi { r }^{ 2 }$
S.A of hemisphere$=2\pi { r }^{ 2 }$
$\therefore $S.A. of solid sphere$>$ S.A of hemisphere
Hence statement is true
Multiple choice maths area and volume of cylinder hollow cylinder volume of cylinder volume of cylinder and cone

A hemispherical bowl has inner radius $5cm$ and outer radius $6cm$. What will be the volume of solid enclosed between the two hemispheres? (Correct upto 2 decimal places)

  1. $904.78 \ {cm}^{3}$
  2. $523.60 \ {cm}^{3}$
  3. $381.18 \ {cm}^{3}$
  4. $190.59 \ {cm}^{3}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The volume of hemispherical shell$= \dfrac{2}{3}\pi*R^{3}-\dfrac{2}{3}\pi*r^{3}$
where R and r are the outer and inner radius of the hemisphere
On solving the equation we get Volume$= 190.59 \ {cm}^{3}$

Multiple choice maths area and volume of cylinder hollow cylinder volume of cylinder volume of cylinder and cone

The surface area of a solid spherical ball of diameter $10\ cm$ is equal to :

  1. $25\pi\ {cm}^2$
  2. $50\pi\ {cm}^2$
  3. $100\pi\ {cm}^2$
  4. $200\pi\ {cm}^2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Given: Diameter of the sphere $= 10\ cm$
Hence, Radius ($r$) of the sphere will be $5\ cm$

We know that, 
Surface area of the sphere is $4\pi r^2$
Therefore, Area will be $4\pi (5)^2 = 100\pi\ {cm}^2$

Multiple choice maths area and volume of cylinder hollow cylinder volume of cylinder volume of cylinder and cone

What will be the Inner and Outer radius of a spherical shell of inner surface area $452.39\ {cm}^2$ and outer surface area $804.25\ {cm}^2$ ? (Surface areas are accurate upto 2 decimal places)

  1. $6 \ cm, 7 \ cm$
  2. $7 \ cm, 8 \ cm$
  3. $6 \ cm, 8 \ cm$
  4. $7 \ cm, 9\ cm$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Inner surface area$=4\pi { \left( inner\quad radius \right)  }^{ 2 }$
$\Rightarrow 4\pi { \left( { r } _{ 1 } \right)  }^{ 2 }=452.39cm^{2}\Rightarrow { r } _{ 1 }^{ 2 }=\cfrac { 452.39\times 7 }{ 4\times 22 } =35.99$
$\Rightarrow { r } _{ 2 }=\sqrt { 35.99 } =5.99\approx 6cm$
Outer surface area$=4\pi { \left( outer\quad radius \right)  }^{ 2 }$
$\Rightarrow 4\pi { \left( { r } _{ 2 } \right)  }^{ 2 }=804.25㎠\Rightarrow { r } _{ 2 }^{ 2 }=\cfrac { 804.25\times 7 }{ 4\times 22 } =63.97$
$\Rightarrow { r } _{ 2 }=\sqrt { 63.97 } =7.99\approx 8cm$