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Posted by Meet Zaid Khan 5 years, 3 months ago (9849313)
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Posted by Sonila Bhutia 5 years, 3 months ago (9713797)
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Gaurav Seth 5 years, 3 months ago (2898529)
The Portuguese and Spanish conquest and colonisation of America was decisively under way by the mid-sixteenth century.
(i)In fact, the most powerful weapon of the Spanish conquerors was not a conventional military weapon at all. It was the germs such as those of smallpox that they carried on their person.
(ii)Because of their long isolation, America’s original inhabitants had no immunity against these diseases that came from Europe.
(iii)Smallpox in particular proved a deadly killer.Once introduced, it spread deep into the continent, ahead even of any Europeans reaching there
(iv)It killed and decimated whole communities, paving the way for conquest.
(v)Guns could be bought or captured and turned against the invaders. But not diseases such as smallpox to which the conquerors were mostly immune.
Posted by Yogith ... 5 years, 3 months ago (9796901)
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?Amrita Deshpremi? 5 years, 3 months ago (9855966)
Yogita Ingle 5 years, 3 months ago (2577571)
Apart from lighting, the light bulbs are used in electronic items as an indicator, traffic signals, indicator lights in cars, etc.
Posted by Dheeraj Singhal 5 years, 3 months ago (9809368)
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Diksha Laniya🐥 5 years ago (10085318)
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Tejasvini S 5 years, 3 months ago (9158229)
Yogita Ingle 5 years, 3 months ago (2577571)
The political conditions of Europe as follows :
(i) The first half of the nineteenth century saw an enormous increase in population all over Europe.
(ii) In most countries, there were more job seekers than employment. Population from rural areas migrated to the cities to live in overcrowded slums.
(iii) Small producers in towns were often faced with stiff competition from imports of cheap machine made goods from England, where industrialisation was more advanced than on the continent.
(iv) In these regions of Europe where the aristocracy still enjoyed power, peasants struggled under the burden of feudal dues and obligations.
(v) The rise of food prices or a year of bad harvest led to widespread pauperism in town and country.
Sonila Bhutia 5 years, 3 months ago (9713797)
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Preetam Laha 5 years, 3 months ago (9851894)
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Yogita Ingle 5 years, 3 months ago (2577571)
In an experimental set up for photoelectric effect, the value of negative potential of collector plate or anode at which the photoelectric current will reduce to zero is called stopping potential (V0) for the given frequency of incident radiation.
Posted by Subobh Sharma 5 years, 3 months ago (8489206)
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Ashritha Reddy J 5 years, 3 months ago (9811055)
Yogita Ingle 5 years, 3 months ago (2577571)
A galaxy is a group of stars, clouds of gas, and dust particles that move together through the universe. There are billions of galaxies in the universe. They probably formed billions of years ago, soon after the universe began.
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Adwitiya Abhishek Kumar 5 years, 2 months ago (10000168)
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Everything Here 5 years, 3 months ago (9185735)
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?Amrita Deshpremi? 5 years, 3 months ago (9855966)
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Khuzaimah Abdulwahhab Shaikh 5 years, 3 months ago (9909301)
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Gaurav Seth 5 years, 3 months ago (2898529)
Physical changes
Those changes in which no new substances are formed, are called physical changes. The changes in state, size, shape and colour of a substance are physical changes. The properties such as state, size, shape and colour of a substance are called its physical properties.
Those changes in which a substance undergoes a change in its physical properties are called physical changes.
The important characteristics of a physical change are as follows:
(1) No new substance is formed in a physical change.
(2) A physical change is a temporary change. A physical change can be easily reversed.
(3) Very little energy is either absorbed or evolved in a physical change.
(4) A temporary change in colour may take place in a physical change.
Examples of physical changes :
Melting of ice (to form water)
Freezing of water (to form ice)
Boiling of water (to form steam
Condensation of steam (to form water
Evaporation of water to form water vapour
Condensation of water vapour (to form liquid water)
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Posted by Pradeep Shakya 5 years, 3 months ago (9611188)
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Posted by Gourav Richa Richa 5 years, 3 months ago (4638266)
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Gaurav Seth 5 years, 3 months ago (2898529)
(iv) Meena went to a bank to withdraw Rs.2000. She asked the cashier to give her Rs.50 and Rs.100 notes only. Meena got 25 notes in all. Find how many notes of Rs.50 and Rs.100 she received.
Solution:
Let the number of Rs.50 notes be A and the number of Rs.100 notes be B
According to the given information,
A + B = 25 ……………………………………………………………………….. (i)
50A + 100B = 2000 ………………………………………………………………(ii)
When equation (i) is multiplied with (ii) we get,
50A + 50B = 1250 …………………………………………………………………..(iii)
Subtracting the equation (iii) from the equation (ii) we get,
50B = 750
B = 15
Substituting in the equation (i) we get,
A = 10
Hence, Manna has 10 notes of Rs.50 and 15 notes of Rs.100.
Posted by Jayank Mishra 5 years, 3 months ago (9241451)
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Gaurav Seth 5 years, 3 months ago (2898529)
1. Find the roots of the following quadratic equations, if they exist, by the method of completing the square:
(i) 2x2 – 7x +3 = 0
(ii) 2x2 + x – 4 = 0
(iii) 4x2 + 4√3x + 3 = 0
(iv) 2x2 + x + 4 = 0
Solutions:
(i) 2x2 – 7x + 3 = 0
⇒ 2x2 – 7x = – 3
Dividing by 2 on both sides, we get
⇒ x2 -7x/2 = -3/2
⇒ x2 -2 × x ×7/4 = -3/2
On adding (7/4)2 to both sides of equation, we get
⇒ (x)2-2×x×7/4 +(7/4)2 = (7/4)2-3/2
⇒ (x-7/4)2 = (49/16) – (3/2)
⇒(x-7/4)2 = 25/16
⇒(x-7/4)2 = ±5/4
⇒ x = 7/4 ± 5/4
⇒ x = 7/4 + 5/4 or x = 7/4 – 5/4
⇒ x = 12/4 or x = 2/4
⇒ x = 3 or x = 1/2
(ii) 2x2 + x – 4 = 0
⇒ 2x2 + x = 4
Dividing both sides of the equation by 2, we get
⇒ x2 +x/2 = 2
Now on adding (1/4)2 to both sides of the equation, we get,
⇒ (x)2 + 2 × x × 1/4 + (1/4)2 = 2 + (1/4)2
⇒ (x + 1/4)2 = 33/16
⇒ x + 1/4 = ± √33/4
⇒ x = ± √33/4 – 1/4
⇒ x = ± √33-1/4
Therefore, either x = √33-1/4 or x = -√33-1/4
(iii) 4x2 + 4√3x + 3 = 0
Converting the equation into a2+2ab+b2 form, we get,
⇒ (2x)2 + 2 × 2x × √3 + (√3)2 = 0
⇒ (2x + √3)2 = 0
⇒ (2x + √3) = 0 and (2x + √3) = 0
Therefore, either x = -√3/2 or x = -√3/2.
(iv) 2x2 + x + 4 = 0
⇒ 2x2 + x = -4
Dividing both sides of the equation by 2, we get
⇒ x2 + 1/2x = 2
⇒ x2 + 2 × x × 1/4 = -2
By adding (1/4)2 to both sides of the equation, we get
⇒ (x)2 + 2 × x × 1/4 + (1/4)2 = (1/4)2 – 2
⇒ (x + 1/4)2 = 1/16 – 2
⇒ (x + 1/4)2 = -31/16
As we know, the square of numbers cannot be negative.
Therefore, there is no real root for the given equation, 2x2 + x + 4 = 0.
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Mohsin Raza 5 years, 3 months ago (9772940)
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