Examveda

The length of the largest possible rod that can be placed in a cubical room is 35√3 m. The surface area of the largest possible sphere that fit within the cubical room $$\left( {{\text{assuming }}\pi = \frac{{22}}{7}} \right)$$    (in sq. m) is

A. 3,500

B. 3,850

C. 2,450

D. 4,250

Answer: Option B

Solution (By Examveda Team)

Mensuration 3D mcq question image
$$\eqalign{ & {\text{Diagonal}} = 35\sqrt 3 \cr & \therefore {\text{The length of largest rod}} = {\text{Diagonal}} = {\text{side}}\sqrt 3 \cr & {\text{side}}\sqrt 3 = 35\sqrt 3 \cr & {\text{side}} = \frac{{35\sqrt 3 }}{{\sqrt 3 }} = 35 \cr & {\text{Side of cube}} = 35 \cr} $$
Mensuration 3D mcq question image
$$\eqalign{ & {\text{Diameter of the sphere }} = {\text{ side of the cube}} \cr & 2 \times {\text{radius}} = {\text{side}} \cr & {\text{radius}} = \frac{{35}}{2}{\text{ cm}} \cr & {\text{Surface area of the sphere}} = 4\pi {r^2} \cr & = 4 \times \frac{{22}}{7} \times \frac{{35}}{2} \times \frac{{35}}{2} \cr & = 3850{\text{ }}{{\text{m}}^2} \cr} $$

This Question Belongs to Arithmetic Ability >> Mensuration 3D

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