Solar System
Moon
As the earth moves around the sun, it is accompanied by the moon. Even though the moon is earth's nearest neighbour in space, it is 3,84,400 km away from the earth’s The moon is 4500 million years old, the same age as the earth. The moon is called the earth's natural satellite because it revolves around the earth.
Why does the moon shine at night? The moon shines because it reflects the sun's light falling on it.
The surface of the moon is made up of plains, valleys and mountains. There are big holes called craters all over the moon. These craters are round and deep. A dark grey dust covers the surface of the moon.
Americans Neil Armstrong, Edwin Aldrin and Michael Collins were the first people to visit the moon. They landed on the moon on 21 July 1969 in their spacecraft Apollo 11. Neil Armstrong was the first person to step on the moon.
Moon
The Moon and Tides
The rising and falling of the level of water in the sea are called tides. Tides are caused by the gravitational pulls of the moon and the sun. The moon attracts the ocean water with stronger force of attraction than that of the sun, because the moon is much closer to the earth than the sun.
Eclipse
An eclipse is a shadow that makes the sun or the moon totally or partially invisible for some time. The sun is the source of light and the earth and the moon are the objects that come in the path of this light and cast their own shadows. As the earth and the moon keep moving, their positions keep changing. Thus, their shadows also keep changing.
Solar Eclipse
Sometimes the moon comes between the sun and the earth. When this happens, the moon. obstructs the light of the sun and casts its shadow on the earth. The people living in this part of the earth can see only a part of the sun or not see it at all. This is a solar eclipse. Once the moon moves out of this position, the sun can be seen again.
If the complete disc of the sun is covered by the shadow of the moon, it is called a total solar eclipse. If more... 
Sun
Luminous Objects
Sun, candle, diya and lamp are examples of objects that produce light. These are called Iuminous objects.
Diya Lamp
Non luminous Objects
The objects that do not produce Tight are called non-luminous objects. Paper, kite and table are examples of non-luminous objects.
Paper Kite Table
Shadow
Light always travels in a straight line. When there is some obstruction in the path of light, we see a shadow. Light is always needed for a shadow to form. Shadows always form on the opposite side of the source of light. Shadows can never form in total darkness. Some objects cast dark shadows while some cast faint shadows.
Sometimes shadows are smaller, and sometimes they are bigger than the actual size. Long shadows are formed in the morning and the evening. Short shadow is formed at noon.
Opaque Objects
Wood and metal are examples of opaque objects. No light can pass through such objects. So they form clear and dark shadows when they are placed in front of a source of light.
Transparent Objects
These objects allow almost all light to pass through them. So transparent objects form very faint shadows (or no shadow at all). Plain glass is an example of a transparent object.
Translucent Objects
Butter paper is an example of a translucent object. Such objects block only a part of the light that passes through them. So they throw a faint shadow.
Sound
A wave of vibrations that spreads from its source. Vibration is the back-and-forth motion of an object.
Sound is produced when we talk, when we strike a steel tumbler with a spoon. Our tongue helps us to make sound. Some sounds are soft, some are loud.
Some sounds are pleasant and some are unpleasant.
Noise
Sound that is loud and unpleasant is called noise. Too much of noise is harmful for our health. Therefore, we should speak softly. We should play television, music system, etc. in low volume so as not to disturb our family and neighbours. 
These changes involve change:
(a) 18 (b) 22
(c) 16 (d) 14
(e) None of these
Answer (c)
Explanation: Pattern followed in 
is Q = + 2
Or,
So, ? = 
Hence, missing number is 16.
Figure Pattern
Figure pattern is a collection of figures that follows a certain sequence or a certain rule.
Example:
How many squares will be there in pattern (31)?
(a) 103 (b) 94
(c) 98 (d) 89
(e) None of these
Answer (b)
Explanation: Number of squares in Pattern (1) = 
Number of squares in Pattern (2) = 
Number of squares in Pattern (3) = 
Number of squares in Pattern (4) = 
Therefore, Number of squares in Pattern (31) = 
Problems Based on Alphabet Test and word
Formation
Alphabet test is one of the most common topic of reasoning where we come across various types of problems as follows:
Example:
Find out the word which cannot be made from the letters of the given word.
PROGRAMMING
(a) Margin (b) Ranger
(b) Paring (d) Ingram
(e) None of these
Answer (b)
Explanation: In more... | S.NO | Instrument | Measurement |
| 1. | Scale | Length |
| 2. | Seismograph | Earthquakes |
| 3. | Thermometer | Temperature |
| 4. | Balance | more...
Distinguishing between Real and Imaginary
Directions: In this chapter, we will discuss the facts or statements which may be real imaginary. In our daily life, we hear many lines which are not possible.
For example: Serena stands on sun.
As we know that no one can stand on sun as it is very hot and as well as far it is awe from the Earth.
Some examples are given below. Read them carefully.
Distinguishing between Facts and Opinions
In this section, we will differentiate between facts and opinions and also find that whether the opinion follows the given fact. Some examples are discussed below to make you understand.
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