Leibnitz Calculator
It was a digital mechanical calculator invented by German mathematician and philosopher Gottfried Wilhelm Leibnitz around 1672 and completed in 1694. Pascal developed the machine because he had to help his father with his work as tax receiver. This was an improvement over the Pascaline. This machine was also able to perform multiplication and division and all the mathematical calculations. Leibnitz's machine used a stepped cylinder. This machine was also called stepped calculator.
Leibnitz calculator was a calculating device. It was the improved form c which one of the following devices?
(A) Abacus
(B) Napier's bones
(C) Pascaline
(D) All of these
(E) None of these
Answer: (C)
Explanation
Correct Option:
(C) Leibnitz calculator was the improved form of pascaline.
Incorrect Options:
(A) Abacus: Was the first calculating device and not the improved form Pascaline. Therefore option (A) is Incorrect.
(B) Napier's bones: Was the calculating device and not the improved ton of Pascaline. Therefore option (B) is Incorrect.
(D) Option (D) is Incorrect.
(E) Option (E) is Incorrect.
Leibnitz's machine used a stepped cylinder. What was its other name?
(A) Stepped calculator
(B) Stepped computer
(C) Stepped device
(D) All of these
(E) None of these
Answer: (A)
Explanation
Correct Option:
(A) Leibnitz's machine was also known as stepped calculator.
Incorrect Options:
(B) Stepped computer- is an Incorrect Option.
(C) Stepped device- is an Incorrect Option.
(D) Option (D) is Incorrect.
(E) Option (E) is Incorrect. 
Mechanical Device - The Pascaline
The calculating machine Pascaline was a mechanical device which was designed and built by the French mathematician-philosopher Blaise Pascal between 1642 and 1644. It could add and subtract numbers. It performed multiplication by repeated addition and division by repeated subtraction. It was also called Pascal's calculator. This machine was capable of doing addition and subtraction with a high speed. It worked on the principle of clockwork mechanism. This machine consisted of chain and toothed wheels. The teeth on each wheel represented numbers from 0 to 9 from right to left and each wheel represented units, tens, hundreds, thousands, ten thousands and so on. This device was used everywhere and became very popular in a short period because of its speed and accuracy.
Pascaline was a calculating machine. What kind of device it was?
(A) Chemical
(B) Mechanical
(C) Electrical
(D) All of these
(E) None of these
Answer: (B)
Explanation
Correct Option:
(B) Pacaline was a mechanical device.
Incorrect Options:
(A) Chemical: Pascaline was a device and no chemical was used. Therefore, option (A) is Incorrect.
(C) Electrical: Since Pascaline was a mechanical device. Therefore, option (C) is Incorrect.
(D) Option (D) is Incorrect.
(E) Option (E) is Incorrect.
Pascaline device was designed and created by the French mathematician. Who was he?
(A) Philosopher Blaise Pascal
(B) Economist Bularo Pascal
(C) Scientist Baciluss Pascal
(D) Physicist Bablo Pascal
(E) None of these
Answer: (A)
Explanation
Correct Option:
(A) Philosopher Blaise Pascal.
Incorrect Options:
(B) Option (B) is Incorrect.
(C) Option (C) is Incorrect.
(D) Option (D) is Incorrect.
(E) Option (E) is Incorrect. 
Information about- Napier's Bone
Napier's bone is an abacus created by John Napier in 17 AD for calculation of products and quotients of numbers. Sir John Napier was a great mathematician of Scotland. This was a manual device. Napier's bone is also called Napier's rod. It was made up of bones and rods. It was capable of doing all the four mathematical operations - addition, subtraction, {multiplication and division. Using the multiplication tables embedded in the rods, multiplication can be reduced to addition operations and division to subtractions.
Napier's bones was created by John Napier. From which country he belonged?
(A) England
(B) Sweden
(C) France
(D) Scotland
(E) Netherlands
Answer: (D)
Explanation
Correct Option:
(D) John Napier belonged to Scotland.
Incorrect Options:
(A) England : John Napier did not belong to England. Therefore, option (A) is incorrect.
(B) Sweden: He did not belong to Sweden. Therefore, option (B) is Incorrect.
(C) France : He did not belong to France. Therefore, option (C) is Incorrect.
(E) Netherlands: He did not belong to Netherlands. Therefore, option (E) is Incorrect.
Napier's bones was used for calculation. It was made up of bones and rods and was capable of doing all the four mathematical operations. What kind of device it was?
(A) Automatic
(B) Electronic
(C) Manual
(D) Electric
(E) None of these
Answer: (C)
Correct Option:
(C) It was a manual device.
Incorrect Options:
(A) Automatic : Napier's bones was a device of 16th century and it worked manually. That's why option (A) is Incorrect.
(B) Electronic : Napier's bones was made up of bones and rods and no electronic things were used. That's why option (B) is Incorrect.
(D) Electric : Napier's bones was a manual device. That's why option (D) is Incorrect.
(E) Option (E) is Incorrect. 
History of Computers
History of computing hardware goes back to many years. The modern computer is the result of continuous process of developing a machine like computer. Finally the computer was developed. John Von Neumann was the man who developed the first computer called ENIAC (Electronic Numerical Integrator and Computer) in 1946. It used to do mathematical operations and store data. Before its invention, a variety of other machines were |used for calculation. The history of computers started from the ancient period when wan used stones, beads, sticks and bones for calculation work. But as the man developed, he felt the need for calculation devices and this need of devices finally led to the development of computer. The earliest calculation device was invented in 500 BC.
First Calculating Device - The Abacus
It was the first calculating device which was invented by the Chinese. It is also called a counting frame and is a calculating tool used primarily in parts of Asia for performing arithmetic processes. The abacus is a manual device. It is typically constructed of various types of hardwoods and comes in varying sizes. The frame of the abacus has a series of vertical rods on which a number of wooden beads are allowed to slide freely. A horizontal beam separates the frame into two sections, known as the upper deck and the lower deck. It is used to count, add and subtract by moving the beads up and down. These beads are marked as unit, tens and hundreds and so on from top to bottom. The beads are moved according to set rules in order to solve problems of calculation. A skilled abacus operator can do addition and subtraction work with the same speed as a modern calculator.
The frame of the abacus consists of series of vertical rods on which number of wooden beads are allowed to ____ freely.
(A) Roll
(B) Attach
(C) Slide
(D) Slip
(E) None of these
Answer: (C)
Explanation
Correct Option:
(C) Slide is the correct option.
Incorrect Options:
(A) Roll: is not used. Therefore, option (A) is Incorrect.
(B) Attach: is not used. Therefore, option (B) is Incorrect.
(D) Slip: is not used. Therefore, option (D) is Incorrect.
(E) Option (E) is Incorrect.
Abacus is used for counting, adding and subtracting. By moving which one of the following things in abacus you can do the calculation?
(A) Balls
(B) Beans
(C) Beads
(D) All of these
(E) None of these
Answer: (C)
Explanation
Correct of Option:
(C) By moving beads you can do the calculation
Incorrect Options:
(A) Balls: are not used for counting in abacus. That's why option (A) is Incorrect.
(B) Beans: are not used for counting in abacus. That's why option (B) is Incorrect.
(D) Option (D) is Incorrect. (E) Option (E) is Incorrect. 
Non Renewable Resources
Nonrenewable resources cannot be regenerated. Oil, coal, natural gas, etc. are some examples of nonrenewable resources.
Coal Liquefied Petroleum Gas (LPG)
Some Important Natural Resources
Nature has given us many important resources for our use. Some of them are given below.
Sun
The sun provides light and warmth to the earth. Plants make their own food only in the presence of sunlight. The solar energy from the sun can be used as renewable source of energy for lightening of streets, cooking food and for many other purposes.
Solar energy
Water
Water is essential for the existence of animals and plants. Energy of flowing water can be used for generating hydroelectric power.
Hydroelectric power
Wind
Wind is an important natural resource. It is utilized as a renewable source of energy.
Many wind mills have been set up all over the world to utilize wind energy.
Wind energy used in wind mill
Land
Land is the most important natural resource. All plants and vegetables grow on land.
Land
Minerals
Mineral is a natural resource that is hidden under the earth. Gold, silver, salt, bauxite and coal are few examples of minerals.
Gold in mineral form Silver in mineral form
Forest
Forests are renewable natural resources. They attract rain and prevent floods.
They conserve soil by replenishing the minerals and give oxygen to the atmosphere.
Forest
more... 
Introduction
Nature gives us many things. For example forest, sun, wind, water, minerals, land, etc. The things that we get from nature is called natural resources. Natural resources are classified into:
(i) Renewable
(ii) Nonrenewable resources.
Renewable Resources
Renewable resources are that resources, which we can use repeatedly and renew.
For example, soil, solar power, wind power, etc.
On the basis of the origin of these resources, they can be classified into:
Biotic: The resources that we derive from living organisms. For example, petrol.
Abiotic: The resources that we derive from non-living things. For example, land, water, air etc.
Solar Energy Water Wind energy 
Motion
Movement of an object from one place to another is called motion. We see many things around us are in motion. Motion takes place when force is applied. For example, a boy throws a ball. Movement of the ball takes place due to the force exerted by the boy.
Boy exerts force to throw ball
Different Types of Motion
There are three types of motion. They are uniform motion, non-uniform motion and circular motion.
Uniform Motion
If a body travels equal distance in equal interval of times then it is called uniform motion. For example, a car travels first 30 kilometres in one hour and next 30 kilometres again in one hour and so on then we say that car has uniform motion.
Car moving with uniform motion
Non Uniform Motion
If a body travels unequal distance in equal interval of times then it is called non uniform motion. For example, a car travels first 30 kilometres in one hour and next
30 kilometres in half an hour then we say that car has non uniform motion.
Car Moving With non-Uniform Motion
Circular Motion
If a body travels on a circular path then it is called circular motion. For example, movements of a merry go round.
Merry go round moves in circular motion
Motion takes place when ___________ is applied.
(a) Force
(b) Mass
(c) Both Force and Mass
(d) None of these
(e) All of these
Answer: (a)
Explanation
For moving any object form one place to another we need to apply force.
Which one of the following is a solid object?
(a) Air
(b) Milk
(c) Computer
(d) All of these
(e) None of these
Answer: (c)
Explanation
Computer is a solid object. Therefore, Option (c) is correct and rest of the options is incorrect.
Anything which has mass and occupies space is called matter.
Matter exists in three different forms, i.e. Solid, Liquid and Gas.
These three forms of matter are called the stages of matter.
Motion takes place when force is applied. 
Matter
Every day we see various things around us. Some of them are heavy, for example, computer. Some of them are light, for example, your pencil. This is because, different objects have different masses. The mass of an object tells us whether an object is heavy or light, or how much heavy or light.
Every object also occupies space. For example, books in your school bag, pencils in your pencil box, water in water bottle, all occupies space.
Anything which has mass and occupies space is called matter.
Matter exists in three different forms.
(i) Solid
(ii) Liquid
(iii) Gas
These three forms of matter are called the stages of matter.
Solid
Objects like books, pen, pencil, cricket bat, doll, tiffin box, school bag etc. have a fixed shape. They do not change their shape if we move them from one container to another. They are called solid object.
Liquid
Substances such as water, milk, oil etc. can flow easily and change their shape according to the shape of the container they are kept in. Such materials are called liquid object.
Gas
Observe when your mother boils water. You will see that some vapour is rising from the boiled water. Now, ask your mother to hold a plate on the rising vapour.
You will find little droplets of water have been formed on the plate.
It means that the vapour that was rising from the boiling water of the container is actually water. Water vapour is the gas form of water. A gas is a state of mater that has no shape and size of its own.
You know that we inhale oxygen. Oxygen is a gas. Gases are all around us. We cannot see them. They are invisible.
Changes of State
The three states of matter, that is, solid, liquid and gas can change their form from one to another.
The process of changing solid into liquid is called
The process of changing liquid into gas is called
The process of changing a gas into liquid (for example, water vapour to water) is called
The process of changing a liquid into solid is called
Ice is frozen water.
Ice cream is frozen milk.
What is matter?
(a) Anything that has mass
(b) Anything that occupies space
(c) Anything that has mass and occupies space
(d) None of these
(e) All of these
Answer: (c)
Explanation
Matters are the objects that occupy space and have mass more... 
First Aid
If any accident happens by chance, first thing, to do is to provide help to the person met with accident to save his precious life. Such help is called first aid.
In this chapter, we’ll learn about the type of first aid, which should be provided to the injured person, in different situations.
Bone Fracture Injury
Look at the following picture of bone fracture injury:
Bone fracture means a bone has been broken. The affected area swells up and it pains a lot, as the supply of the blood to the affected part get blocked.
First Aid in Case of Fracture
Do not let the affected area to move. Support the injured portion with a stick and clothes in a comfortable position. Take the patient as soon as possible to the hospital.
Burn Injury
Look at the following picture of affected part of the body from burn injury:
One may get burn injury due to fire by electricity, explosive chemicals, hot oil, steam etc.
First Aid
Wash the burnt part with clean water. Antibiotic powder cream may be applied over the affected area. Light dressing can be done if the injury is not serious.
If the injury is due to chemical, pour, maximum possible amount of water to remove chemicals from the burnt area. Take the patient to the doctor.
Nose Bleeding
Look at the following picture of nose bleeding:
We often see people bleeding from the nose. It means blood is coming out from the blood vessels.
First Aid
Do not get panic. Help the patient to lie down in an easy position keeping the head downward.
It would stop bleeding. If bleeding doesn't stop then hold the nose between the thumb and the finger for 5 -10 minutes. Ice can be applied over the nose.
During the whole process, injured person breathe through the mouth. If not cured take the patient to the nearby doctor.
Injury Due to Animal Bite
Animals like dog, cat, monkey etc. bite people. The germs from their body enter the body of injured person, which can be dangerous.
First Aid
Wash the affected part with Dettol and antiseptic soap. Put antibiotic powder or cream over the wound and take the patient to the doctor.
Insect Bite
Insects like more... 
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