## Revision Notes for ICSE Class 10 Maths Chapter 20 - Free PDF Download

## FAQs on ICSE Class 10 Mathematics Revision Notes Chapter 20 - Cylinder, Cone and Sphere

**1. According to concepts taught in chapter 20 of ICSE Class 10 Maths, solve this:A circular cylinder has a height of 20 cm and a radius of 7 cm. (i) Calculate the volume and (ii)surface area **

To attempt this type of question, you need to make sure that you know each and every formula and also have an idea of how to and where to apply the formula.

**For Instance, For a Given Question The Formula Can Be Applied As: **

Considering a circular cylinder of height h = 20 cm and radius r = 7 cm (i) Volume of cylinder = r

^{2}h = 22/7 x 72 x 20 cm^{3}= 3080 cm^{3}The area of a cylinder is equal to 2πr (h + r)= 2 x 22/7 x 7(20 + 7) cm

^{2}= 2 x 22 x 27 cm^{3}= 1188 cm^{3}

**2. According to concepts taught in chapter 20 of ICSE Class 10 Maths, to cast a hollow cylinder of external diameter 20 cm, 0.25 cm thick and 15 cm long from a solid cylinder of diameter 2 cm, how much length must be added?**

Since the external diameter of the hollow cylinder is 20 cm,

There is a radius of 10 cm equal to R.

The thickness is 0.25 cm.

Therefore, the internal radius = (10 – 0.25 = 9.75 cm = r)

The length of the cylinder (h) is 15 cm

**Now,**

Volume = πh (R^{2} – r^{2}) = π x 15(102 – 9.752) = 15 π (100 – 95.0625)

= 15 π x 4.9375 cm^{3}

**Now,**

Solid cylindrical diameter = 2 cm

Therefore, radius (r) = 1 cm, length (h) = 1 cm and volume (V) = πr^{2}h = πh cm^{3}

Accordingly, based on the condition given in the question

πh = 15 π x 4.9375

h = 15 x 4.9375

h = 74.0625

Therefore, the length of the solid cylinder is 74.0625 cm

**3. According to concepts taught in chapter 20 of ICSE Class 10 Maths, solve the following:**

**A cylindrical shape has a diameter of 20 cm. Its radius is 100 sq cm. **

**Find:**

**The cylinder dimensions are correct to one decimal place.****The volume is also correct to one decimal place.**

**Given,**

The cylinder's diameter is 20 cm

So, the radius (r) = 10 cm

surface area = 100 cm^{2}

Height = h cm

**(i) Curved surface area = 2πrh**

So,

2πrh = 100 cm^{2}

2 x 22/7 x 10 x h = 100

h = (100 x 7)/ (22 x 10 x 2) = 35/22

h = 1.6 cm

**(ii) Volume of the cylinder = πr ^{2}h**

= 22/7 x 10 x 10 x 1.6

= 502.9 cm^{3}

**4. How will Revision Notes help you score well for class 10 ICSE Maths? **

**Revision Notes Help You Score Well For Class 10 Icse Maths In The Following Ways: **

Saves Time: All the concepts from the chapter are summarized here in one document so that students can review them quickly. This saves students time and energy searching for formulas and concepts. All formulas and concepts for each chapter have been extracted here into a single note.

These notes have been designed by subject experts with an emphasis on simplicity and precision, covering almost all areas such as cylinder, cone and sphere.

These notes along with the sample papers available at vedantu are detailed and could assist students in getting good marks in their 10th standard as well as their post-secondary education.

**5. Why should one write notes for Mathematics class 10th ICSE paper? **

**One Should Write Notes For Mathematics Class 10th Icse Paper For The Following Reasons: **

Creating handwritten notes is always considered the best way to truly grasp the concept and score well on an exam.

When it comes to Class 10th Maths, there is no denying that it is considered as one of the toughest subjects in your curriculum, thus having notes by your side is an all-time essential.

Class 10th Maths is full of numerical, graphs and formulas thus making your own notes and highlighting them is the only way you can catch hold of them.

If students want to be able to develop their answering capacity and speed during the exam, they should make their own revision notes.

Having handy notes means better revision and better revision means the best result so make sure you prepare your own notes.