# A hollow cylinder of negligible thickness and radius r is mounted by a hollow sphere of same radius. The height of the cylinder is h. If the solid formed is to be painted. What is the total surface area that has to be painted?

A.$2\pi rh + 4\pi {r^2}$

B.$2\pi rh + \pi {r^2}$

C.$2\pi rh + 3\pi {r^2}$

D. None of the above

Last updated date: 18th Mar 2023

•

Total views: 304.8k

•

Views today: 2.85k

Answer

Verified

304.8k+ views

Hint: We are going to solve the given problem using formulae for finding the surface area cylinder and sphere.

Given that radius of hollow cylinder is r and height is h. and

Radius of the hollow sphere is also r.

The cylinder is mounted by the hollow sphere. We are painting the solid formed.

Total surface area painted = curved surface area of cylinder + curved surface area of sphere + area of base circle.

Let A be the total surface area formed.

$A = 2\pi rh + 2\pi {r^2} + \pi {r^2}$

$A = 2\pi rh + 3\pi {r^2}$

Note:

Surface area of any object is the area of an outer part of that object. It includes all faces of the object.

Given that radius of hollow cylinder is r and height is h. and

Radius of the hollow sphere is also r.

The cylinder is mounted by the hollow sphere. We are painting the solid formed.

Total surface area painted = curved surface area of cylinder + curved surface area of sphere + area of base circle.

Let A be the total surface area formed.

$A = 2\pi rh + 2\pi {r^2} + \pi {r^2}$

$A = 2\pi rh + 3\pi {r^2}$

Note:

Surface area of any object is the area of an outer part of that object. It includes all faces of the object.

Recently Updated Pages

If a spring has a period T and is cut into the n equal class 11 physics CBSE

A planet moves around the sun in nearly circular orbit class 11 physics CBSE

In any triangle AB2 BC4 CA3 and D is the midpoint of class 11 maths JEE_Main

In a Delta ABC 2asin dfracAB+C2 is equal to IIT Screening class 11 maths JEE_Main

If in aDelta ABCangle A 45circ angle C 60circ then class 11 maths JEE_Main

If in a triangle rmABC side a sqrt 3 + 1rmcm and angle class 11 maths JEE_Main

Trending doubts

Difference Between Plant Cell and Animal Cell

Write an application to the principal requesting five class 10 english CBSE

Ray optics is valid when characteristic dimensions class 12 physics CBSE

Give 10 examples for herbs , shrubs , climbers , creepers

Write a letter to the principal requesting him to grant class 10 english CBSE

List out three methods of soil conservation

Epipetalous and syngenesious stamens occur in aSolanaceae class 11 biology CBSE

Change the following sentences into negative and interrogative class 10 english CBSE

A Short Paragraph on our Country India