Watch Wonders of The World

Google initiated a new education project called the World Wonders Project. It offers various monumental sites of historical, architectural and natural interest. It includes monuments, memorials, cathedrals, castles, landscapes.

Along with a 3D street view, there is ample information available to enrich your knowledge. The only caveat is, currently no Indian site is covered. Hope we shall see it very soon.

CBSE Class 9- CH5: Introduction to Euclid's Geometry

Fragment of Euclid's Elements
source: wikicommons

NCERT Chapter Solutions
and Other Q & A

Exercise 5.1

Q1: Which of the following statements are true and which are false? Give reasons for your answers.

(i) Only one line can pass through a single point.

(ii) There are an infinite number of lines which pass through two distinct points.

(iii) A terminated line can be produced indefinitely on both the sides.

(iv) If two circles are equal, then their radii are equal.

(v) As shown in Fig. below, if AB = PQ and PQ = XY, then AB = XY.

Answer:

Plurals with Different Meanings

Some Nouns have same meaning in singular form but have different meanings in plural form.

A few are listed here:

Colours:

1. Hues
2. Regiment (unit of army)

 Compasses:

1. Magnetic compasses used for navigation
2. Instruments used in geometry

How to learn naming Chemical Formulae?

Chemicals
(src:deviantart)

Nomenclature of Simple Inorganic compounds.

1. A formula is a shorthand notation used to identify the composition of a molecule or compound.

2. For example chemical formula of water is H₂O. It includes the symbol of each element (e.g. Hydrogen:H and Oxygen:O)  in the molecule, along with numerical subscripts to show how many atoms of each element are present.

3. Most of the inorganic compounds are binary compounds i.e. it consists of two elements. Some are ternary i.e. contain more than two elements.

CBSE Class 10 - Science - SA1 Paper

Class 10 - Science - SA1 - Paper (2010)

NTSE SAT Quiz-13 (Maths) / Class 8 Maths

NTSE SAT Quiz-13 (Maths)

Q1: One third of a number is greater then one fourth of its successor by 1, find the number.

(a) 5
(b) 15
(c) 20
(d) 25

Class 11 - Physics - CH3 - Motion In a Straight Line (Part-2)

Motion in straight line!
(source:clker.com)

NCERT Chapter Solutions (Q14-onwards)

For Questions (1-13) see page.

Q 3.14: A man walks on a straight road from his home to a market 2.5 km away with a speed of

5 km/hr. Finding the market closed, he instantly turns and walks back home with a speed of

7.5 km /hr. What is the

(a) magnitude of average velocity, and

(b) average speed of the man

over the interval of time

(i) 0 to 30 min,

(ii) 0 to 50 min,

(iii) 0 to 40 min ?

[Note: You will appreciate from this exercise why it is better to define average speed as total path length divided by time, and not as magnitude of average velocity. You would not like to tell the tired man on his return home that his average speed was zero !]

Answer: