Explore topic-wise InterviewSolutions in .

This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

51.

What is the radius of a sphere having volume of 4851cm^3? (Take π = \(\frac{22}{7}\))(a) 9 cm(b) 11 cm(c) 10.5 cm(d) 11.3 cmI had been asked this question in an internship interview.My question comes from Volume of a Sphere in section Surface Areas and Volumes of Mathematics – Class 9

Answer»

Correct option is (c) 10.5 CM

The explanation: We know that VOLUME of a sphere of radius r is EQUAL to \(\frac{4}{3} πr^3\).

\(\frac{4}{3} πr^3\) = 4851

\(\frac{4}{3} * \frac{22}{7} * r^3\) = 4851

\(r^3 = \frac{9261}{8}\)

Therefore, r = \(\frac{21}{2}\) = 10.5 cm.
Discussion
52.

Curved surface area of hemisphere of radius “r” is equal to __________(a) 2πr^2(b) 4πr^2(c) 3πr^2(d) πr^2I got this question during a job interview.I'm obligated to ask this question of Surface Area of a Sphere in chapter Surface Areas and Volumes of Mathematics – Class 9

Answer» RIGHT choice is (a) 2πr^2

To elaborate: Hemisphere is created when a SPHERE is DIVIDED in two equal parts.

Hence, the curved surface are of a hemisphere = \(\FRAC{Surface \,AREA \,of \,a \,sphere}{2}\)

= \(\frac{4πr^2}{2}\)

= 2πr^2.
Discussion
53.

A transparent cylinder shown in the figure below is a right circular cylinder.(a) True(b) FalseThe question was posed to me in an online quiz.Enquiry is from Surface Area of a Right Circular Cylinder in portion Surface Areas and Volumes of Mathematics – Class 9

Answer»

The correct CHOICE is (B) False

Easiest EXPLANATION: The cylinder shown in the figure is circular but it is not PERPENDICULAR to the BASE so we can’t say it is right circular cylinder.

A right circular cylinder is shown in the figure below. We can see that it is at the right angle to the base.
Discussion