Explore topic-wise InterviewSolutions in .

A LASER beam is a source of very intense, monochromatic and unidirectional beam.By sending a laser beam towards the moon instead of sound waves, the echo method becomes sueful in finding the distance of moon from the earth. If t is the total time taken by laser beam in going towards moon and back, then distance o moon from earth's surface is given by 

s = c x t/2

Where c = 3 x 10⁸ m/s, is the velocity of laser beam.

1. The Ottoman Turks captured Constantinople. the capital of Byzantine Empire. in 1453 AD. 

2. All land trade routes joining Asia and Europe passed through this city. 

3. It stopped the flow of valuable goods from the countries in the east. Therefore, the European countries felt the necessity of finding new sea routes to Asia.

In North Rajasthan on the bank of River Ghaghar places of Indus-Saraswati civilization were discovered. This place was located in district Hanumangarh 4500 years ago at the bank of river Saraswati (Ghaghar). In Kalibangan, two dunes are found of city planning. There is a security wall around both dunes. Evidence of tilled land found in Kalibangan is the oldest. Brick walls were joined by soil which made the walls strong and durable. Individual and public drainage system is an example of highly cleanliness system.

At present here Ghaghar river flows known as Saraswati in ancient times. Bricked drains were built for the disposal of waste water. Tools made up of copper are the example of its development. Its town planning is similar to Indus town planning. Three samadhis are found which shows the respect towards dead persons of this civilization. The reasons of decline of this civilization may be drought or change in the direction of river, etc.

He was a great democratic ruler of Greece. By his reforms he made Athens democratically strong and wide. He believed in equal justice for all. In his period art, literature, music and philosophy developed up to a great extent.

Many dramas of happiness and tragedies were played in Athens. Socrates, a world famous philosopher, gave stress on knowledge and character belonged to Greek Civilization. Plato and Aristotle belonged to Peracles era. Homer’s world famous treaties Iliad and Odyssey were composed.

Temple of goddess Athena is a marvelous piece of architecture belonged to this era. Herodotus and Thucydides were great historians. Pythagoras and Hippocrates were mathematicians.

Due to these achievements Parades era in history of Greek is called the golden period. According to Professor David, Parades era of Greek history is not only the golden period of Greek history but the history of the world.

Life of Sparta: It had fear of attacks from neighbouring nations hence autocratic military rule was established here.

To make children strong, military education and training was compulsory for the people to face difficulties in life. Those children who were weak thrown from the Tesitus hill to die.

Sparta succeeded in preparing citizens who were blind followers, obedient and brave warriors but its contribution in the field of science, art, philosophy, literature is negligible.

Ahad is located in Udaipur district, which was the centre of Bronze age culture of . the South-East Rajasthan. This 5000 years old civilization was developed in the valley of Bedach, Banas rivers. Due to availability of copper in this area, people living here made metallic tools which made it a copper-skilled centre. Extension of this civilization is evidence from the near by places Gilund, Balathal, Bagaur, etc. It had relations with Navadatoli, Nagda, Eran, Kaitha till Kuchchh in.North Gujarat. Its connection was with 4000 years old civilizations. Black and red earthen pots found here have similarity in skill, size and manufacturing are evidence of it.

A Mound of Deads. (Murdo Ka Tila)

Aahad civilization which was famous as (Tamravati or Dhulkot).

It was developed between the valley of Hwang-Ho and Yang-Tse-Kiang rivers. Chinese script was picture based in the later developed their own alphabets. Mongolians gave birth to this civilization and developed it. According to available historical facts and their scientific analysis, it is believed that China’s systematic, political history starts with 2852 BC with a ruler named ‘Fusi’, Among China’s dynasty chief kings were of Shang, Chou, Huan, Sui, Tang, Shung dynasties.

Features of Chinese Civilization Social Life: 

Chinese society was divided into four classes:

1. Mandarins 

2. Farmers 

3. Artisans 

4. Traders.

People who joined army were either very poor, lazy and those who had different characters. According to H.A. Davis ‘China was the only nation in ancient period which was peacefully organized and being military man was an ‘insult’ in the society. Joint family system was prevailed with eldest male member as the head. Great stress was given on high morality in life. Women had no respect in the society. Pardah system and divorce system were prevailed.

Economie Life: Agriculture of rice, tea in large scale. Irrigation by canal system. Rearing of sheep, pigs, cows, dogs, etc. Sericulture (making of silk cloth) was the main occupation. Handicraft, ceramics were important occupations. Export of silk, salt, raw iron, fur, fish, etc. was done to India in a large scale.

1. Mesopotamia, a word of Greek language, means land between two rivers. The modern name of this country is Iraq. This region is irrigated by two rivers, i.e., Dajla and Farat. It is also called fertile semi-lunar because of its semi-circular shape and fertility. 

2. In ancient time southern part of this region was called ‘Sumer’, it was the centre of civilization. North-eastern part of Sumer was called Babul (Babylon) and Akkad, while Northern upland (Citadel) was called Aseria.

3. Sumerian people who came from North mountaineous region later settled in Mesopotamia and developed a very prosperous civilization. They established a Town- State government. Ur, Lagash, Erek, and Eridu were famous TownStates. In 2500 BC, Sagan I came from Akkad, won the Sumerian people and established a strong state by mixing Sumer and Akkad. But by 2100 BC, people of Akkad also lost their state and a new dynasty named Sami originated in Babylon and Babylon became the capital of this new state. The most famous king of Hammurabi controlled the war of different states and implemented equal laws and made a vast strong nation. Babylonian civilization also based on Sumerian civilization. Later in around 1100612 BC, Aserian people established their administration or empire in Mesopotamia. They established a vast empire after winning Syrea, Philistine, Phinesia, etc. Later Caldean people defeated Aserians and established a second Babylonian empire during 612 BC to 539 BC but they were also defeated by Parsis in 539 BC. In this way, civilizations of Sumerian, Babylonian, Aserian and Caldean equally known as Mesopotamian Civilization. 

4. Babylonian king Hamurabi formed a Code of Conduct for his subjects which is the oldest of those times. It was engraved of 8 feet high rock. His principle of punishment was based on Tit-for-Tat’ and ‘Blood against Blood’. 

5. King was considered the representative of God on earth. After king and his family, Purohit was the second who might be the administrator before monarchial system. In middle class, feudals, traders and shopkeepers were included. Dasas (Slaves) held the meanest position in the society. Military got importance due to continuous war.

Balathal civilization is located in Vallabhnagar tehsil of district Udaipur.

The Great Wall of China.

Aryans did not come from outside India as they were the original habitants of India.

Correct Answer is: (a) Harappa 

The French Revolution gave the principles of liberty equality and fraternity to the world.

The British established the East India Company to carry out trade in India.

Harappa and Mohenjodaro

He was known as the Grahapati.

These instruments were harp, flute, snail, shell, cymbals and jhanj.

In order to keep the border safe from the Huns.

They are located in Pakistan.

Rai Bahadur Dayaram Sahni discovered Harappa in 1921 AD and Rakhal Das Banrejee discovered Mohenjodaro in 1922 AD.

The ruler named Minis established political structure of Egypt.

He was known as Pharoh.

Experts have tried to locate their native place in North Pole, Europe, Central, Asia, etc. but the latest research indicates, India to be their native place. According to Dr. Sampurnanand and Dr. Avinash Chandra Das, the Aryans were the inhabitants of the land of the seven rivers. From the area of seven rivers their groups moved towards Iran in West, Central Asia, Western Asia and to different countries of Europe. They moved to other parts of India too.

Assuming the average age of man as 100 years, it was divided into four Ashramas of 25 years each. 

These Ashramas were:

1. Brahmachaiya Ashrama 

2. Grahastha Ashrama 

3. Vanaprastha Ashrama 

4. Sanyasa Ashrama

The Gizeh Pyramid was built by Pharaoh Cheops in 3000 BC. It is built in an area of 32 acres and is 484 ft. high and 755 ft. long. It is an excellent piece of the Egyptian architecture.

The Renaissance, the Reformation and the geographical discoveries laid the foundation of the modern era.

(b) Chinese Civilization

(c) Greater than mg

Boy has to apply more force at point B as compared to point A, because point B is at least distance from the hinge of the door while point A is at maximum distance from hinge of the door. Opening of door applies a moment, which is. given by,

M = F × perpendicular distance

F ∝ \(\frac{1}{distance}\)

More is the distance from the axis of rotation less will be the force.

(i) If the force is applied at the handle of the door to open it, only small force is required. That means larger the perpendicular distance, lesser is the force needed to turn the body.

(ii) From this it is easy to conclude that the turning effect of a body about an axis depends not only on the magnitude of the force but also on the perpendicular distance of the line of action of the applied force from the axis of rotation

Given,

Radius = 5 cm

Angle subtended at the centre ‘O’

Area of sector of circle = 5π cm²

We know that,

Area of the sector = θ/360 ∗ πr²

= θ/360 ∗ π5²

= 5πθ/72

From the question, we can equate

5π  = 5πθ/72

On solving, we have

θ = 72°

Hence, the angle subtended at the centre of circle is 72°

Area of sector = 5π cm² 

Radius = 5 cm

5π = \(\frac{θ}{360°}\timesπ\times25\)

q = \(\frac{5π\times360°}{25π}\) = 72°

Diameter of the semicircular protractor = 14 cm

Radius = 14/2 cm = 7 cm

Perimeter of semicircle = πr + d

Perimeter of semicircular protractor = 22/7 x 7 + 14 

= 22 + 14 = 36 cm

The perimeter of the semicircular protractor is 36 cm.

The correct option is:

(D) None of these

Radius = r = 6 cm and θ = 30°

Area of sector = θ/360 (πr²)

= 30/360 x 3.14 x (6)²

= 9.42 cm²

Diameters are in the ratio 1:2:3

So, let the diameters of the concentric circles be 2r, 4r and 6r.

∴ Radius of the circles be r, 2r, 3r respectively.

Now, Area of the outermost circle = π (Radius)² = π (3r)² = 9πr²

Area of the middle circle = π (Radius)² = π (2r)² = 4πr²

Area of the innermost circle = π (Radius)² = π (r)² = πr²

Now, Area of the middle region = Area of middle circle – Area of the innermost circle

= 4πr² - πr² = 3πr²

Now, Area of the outer region = Area of outermost circle – Area of the middle circle

= 9πr² - 4πr² = 5πr²

Required ratio = Area of inner circle: Area of the middle region: Area of the outer region

= πr² : 3πr² : 5πr²

⇒ Required Ratio is 1:3:5

Given, 

Radius of sector = 4 cm 

Angle of sector = 30° 

Area of sector = \(\frac{θ}{360°}\timesπr^2\)

= \(\frac{30}{360}\timesπ\times16\)

= \(\frac{1}{12}\timesπ\times16\) 

= \(\frac{4π}{3}\) cm²

Given,

Radius = 4 cm

Angle subtended at the centre O = 30°

We know that,

Area of the sector = θ/360 ∗ πr²

= 30/360 ∗ π4² =1/12 ∗ π16 = 4π/3

Therefore, the area of the sector of the circle = 4π/3 cm² 

Given,

Radius = 8 cm

Angle subtended at the centre O = 135°

We know that,

Area of the sector = θ/360 ∗ πr²

Area of the sector = 135/360 ∗ π8²

= 24π cm²

Therefore, Area of the sector calculated is 24π cm²

(i) Edge of the given cube = 8 cm

Volume of the given cube = (Edge)³ = (8)³ = 8 x 8 x 8 = 512 cm³ 

Total surface area of a cube = 6(Edge)² = 6 x (8)² = 384 cm² 

(ii) Edge of the given cube = 2 m 40 cm = 2.40 m

Volume of a cube = (Edge)³ 

Volume of the given cube = (2.40)³ = 2.40 x 2.40 x 2.40 = 13.824 m² 

Total surface area of the given cube = 6 x 2.4 x 2.4 = 34.56 m² 

From the given figure, ∠POQ = 60° 

∠QOR = x° 

∠ROS = 47° But 

∠POQ + ∠QOR + ∠ROS = 180° 

⇒ 60° + x° + 47° = 180° 

⇒ x° + 107° = 180° 

⇒ x° = 180°- 107°

∴ x° = 73°

 Given, l(AB) = 5 cm, l(BP) = 2 cm,

 l(AP) = 3.4 cm … [Given]

 r Since, 2 < 3.4 < 5 

∴ l(BP) < l(AP) < l(AB)

 i.e., seg BP < seg AP < seg AB

Correct option is: (C) parallel

Collinear points:

1. Points A, E, H and C. 

2. Points B, E, I and D.

Non-collinear points: 

Points B, G, F and I

i. Parallel lines: 

a. line l and line n 

b. line p, line q, line r and line s 

ii. Concurrent Lines: line q, line m, line n 

Point of Concurrence: point S 

iii. line l, line PT, line PR, line PV, line RT, line RV and line TV.

Line Segments:

seg UV, seg OY, seg OX, seg OV and seg OU

Rays:

ray OV, ray OX, ray OY and ray UV.

Three non-collinear points form a triangle.

i. Co-ordinate of first point is 3.

Co-ordinate of second point is 6.

Since, 6 > 3

∴ Distance between the points = 6 – 3 = 3

ii. Co-ordinate of first point is -9.

 Co-ordinate of second point is -1.

 Since, -1 > -9 

∴ Distance between the points = -1 – (-9) = -1+9 = 8

iii. Co-ordinate of first point is -4.

 Co-ordinate of second point is 5. 

 Since, 5 > -4 

∴ Distance between the points = 5 – (-4) = 5 + 4 = 9

iv. Co-ordinate of first point is 0. 

 Co-ordinate of second point is -2. Since, 

0 > – 2 

∴ Distance between the points = 0 – (-2) = 0 + 2 = 2

v. Co-ordinate of first point is x + 3. 

 Co-ordinate of second point is x – 3. 

 Since, x + 3 > x – 3

∴ Distance between the points = x + 3 – (x – 3)

= x + 3 – x + 3 = 3 + 3 = 6

vi. Co-ordinate of first point is -25. 

Co-ordinate of second point is -47. 

Since, -25 > -47 

∴ Distance between the points = -25 – (-47) = -25 + 47 = 22

vii. Co-ordinate of first point is 80.

 Co-ordinate of second point is -85. 

 Since, 80 > -85 

∴ Distance between the points = 80 – (-85) = 80 + 85 = 165