Self Studies

Surface Areas and Volumes Test - 22

Result Self Studies

Surface Areas and Volumes Test - 22
  • Score

    -

    out of -
  • Rank

    -

    out of -
TIME Taken - -
Self Studies

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Self Studies Self Studies
Weekly Quiz Competition
  • Question 1
    1 / -0
    The amount of three-dimensional space occupied by an object is called?
    Solution
    Volume is the quantity of three-dimensional space enclosed by a closed surface. For example: Cylinder, Cuboid etc
  • Question 2
    1 / -0
    If all three parameters of a cuboid are in meters$$(m)$$, then unit of volume of a cuboid is:
    Solution
    As the volume of a cube is $$length\times length \times length $$
    If lengths of all are measured in meters.
    Then the volume will be measured in $$m^3$$.
    Hence, the answer is $$m^{3}$$.
  • Question 3
    1 / -0
    If the circumference of base of a hemisphere is $$2\pi$$ then its volume is _________ $$cm^3$$.
    Solution
    The circumference of base of a hemisphere $$=2\pi$$
    $$\therefore 2\pi r=2 \pi$$
    $$\therefore r=1$$
    Its volume $$= \dfrac{2}{3}\pi (r)^3$$
    $$= \dfrac{2}{3}\pi (1)^3 =\dfrac{2}{3}\pi \ cm^3$$
  • Question 4
    1 / -0
    The surface area of a cube of side $$27\ \text{cm}$$ is
    Solution
    Let, the given side of square$$=a=27\ \text{cm}$$
    Surface area of cube$$=6a^2$$
                                       $$=6(27)^2\ \text{cm}^2$$
                                       $$=4374\ \text{cm}^2$$
  • Question 5
    1 / -0
    Find the surface area of a $$10cm \times 4cm \times 3cm$$ brick:
    Solution

    The formula for calculating the surface area of a cuboid of dimensions :


    $$ l \times b \times h $$ is :


    $$ 2\times (l\times b+b\times h+h\times l) $$


    Substituting,


    $$l=10cm$$


    $$b=4cm$$


    $$h=3cm$$


    Surface area = $$ 2\times (10\times 4+4\times 3+3\times 10) $$


    $$ = 2\times (40 + 12 + 30) $$


    $$ = 2\times 82 { cm }^{ 2 } $$


    $$ = 164 { cm }^{ 2 } $$


    Hence, the answer is option (C)

  • Question 6
    1 / -0
    Given a sphere with the radius $$7\ cm$$. Find the volume of this sphere. Take $$\pi$$ as $$3.14$$.
    Solution
    Volume of sphere = $$\dfrac{4}{3} \pi r^3$$

    $$V=\dfrac{4}{3} (3.14) (7)^3$$

    $$V=\dfrac{4}{3} \times 3.14 \times 343=1436.03 \ cm^3$$
  • Question 7
    1 / -0
    The surface area of a solid hemisphere with radius $$r$$ is
    Solution
    Surface area of a solid sphere with radius $$r$$ is $$4 \pi r^2$$
    A solid sphere can be divided into two equal hemispheres with a flat surface and a curved surface.
    Curved surface area of a solid hemisphere will be half the surface area of solid sphere.
    Hence, curved surface area of solid hemisphere $$=\dfrac{1}{2}*4 \pi r^2 = 2 \pi r^2$$
    And, flat surface area of hemisphere will be the area of circle with radius $$r$$.
    Hence, flat surface area of hemisphere $$=\pi r^2$$
    Total surface area of a solid hemisphere with radius $$r$$ is, $$S=2\pi r^2+\pi r^2 = 3\pi r^2$$

  • Question 8
    1 / -0
    The radius of a hemispherical balloon increases from 6 cm to 12 cm as air is being pumped into it. The ratios of the surface areas of the balloon in the two cases is
    Solution
    Total surface area of a Hemisphere $$=2\pi r^2 + \pi r^2 = 3\pi r^2$$
    $$r=6,Surface\ area=3 \pi (6)^2=36$$
    $$r=12,Surface\ area=3 \pi (12)^2=144$$
    Ratio = $$36:144$$
    =$$1:4$$
  • Question 9
    1 / -0
    The water for a factory is stored in a hemispherical tank whose internal diameter is $$14\ m$$. The tank contains $$50$$ kilo litres of water. Water is pumped into the tank to fill to its capacity. Calculate the volume of water pumped into the tank.
    Solution
    Radius of hemispherical tank, $$ r= 7$$ m
    So volume of water to be pumped $$=$$ Volume of hemispherical tank $$-50$$ kl
    $$\because 1\ kl = 1\ m^3$$
    $$\Rightarrow \dfrac{2}{3} \pi r^3 - 50\ m^3$$
    $$\Rightarrow \dfrac{2}{3} \times \dfrac{22}{7}\times \left(7\right)^3 - 50\ m^3$$
    $$\Rightarrow 718.67-50\ m^3$$
    $$\Rightarrow 668.67\ m^3$$
    Hence, option B is correct.
  • Question 10
    1 / -0
    The radius of a sphere is $$2r$$, then its volume will be:
    Solution
    As,$$r=2r$$
    Volume of sphere$$=\frac{4}{3} \pi (2r)^3=\frac{32}{3} \pi r^3$$
Self Studies
User
Question Analysis
  • Correct -

  • Wrong -

  • Skipped -

My Perfomance
  • Score

    -

    out of -
  • Rank

    -

    out of -
Re-Attempt Weekly Quiz Competition
Self Studies Get latest Exam Updates
& Study Material Alerts!
No, Thanks
Self Studies
Click on Allow to receive notifications
Allow Notification
Self Studies
Self Studies Self Studies
To enable notifications follow this 2 steps:
  • First Click on Secure Icon Self Studies
  • Second click on the toggle icon
Allow Notification
Get latest Exam Updates & FREE Study Material Alerts!
Self Studies ×
Open Now