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# Homework Help

Ask questions which are clear, concise and easy to understand.

Why bases does not react with metal carbonate or metal bicarbonate?

Posted by Gagan Singh (May 24, 2017 8:49 p.m.) (Question ID: 5473)

• Metal Carbonates do not react with bases because metal carbonates are itself bases.

So base when added to base gives no reaction.

Answered by Payal Singh (May 24, 2017 8:51 p.m.)
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GIVE EXAMPLE OF POLYNOMIALS p(x),g(x)and r(x), which satisfy the division algorithm and:

1. deg p(x)=deg q(x)
2. deg q(x)=deg r(x)
3. deg r(x)=0

Posted by Archith jayalal (May 25, 2017 9:15 a.m.) (Question ID: 5472)

• THANK YOU VERY MUCH.........

Posted by Archith jayalal (May 24, 2017 7:27 p.m.)
• We can write many such examples

(i) deg p(x) = deg q(x)

P(x) = x2, q(x) = x2, g(x) = 1, R(x) = 0

(ii) deg q(x) = deg r(x)

q(x) = x , R(x) = x , p(x) = x2 + x, g(x) = x2

(iii) deg r(x) = 0

q(x) = 1 , R(x) = 1 , p(x) = x+1, g(x) = x

Answered by Payal Singh (May 25, 2017 9:15 a.m.)
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Let a b c p be rational numbers such that p is not perfect cube . if a +bp^1/3+cp^2/3=0 then prove a=b=c=0

Posted by Sidharth Thakur (May 25, 2017 5:31 p.m.) (Question ID: 5471)

• As p is not a perfect cube. Hence p1/3 and  p1/3 , p2/3  are irrartional numbers. Then we have b p1/3 +c p2/3   as irrational and a as rational. As sum of a rational number and an irrational number cannot give us a zero as answer so all the coefficiants (a,b and c) must be zero in general.

Answered by Shivam .G (May 25, 2017 5:19 p.m.)
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• Molality  of NaOH is 1.25,percent by weight of NaOH  is.......
• The only  primary  alcohol that can be prepared by the indirect hydration of alkene is.....
Posted by MUDASSIR MOHIUDDIN INAMDAR (May 24, 2017 4:36 p.m.) (Question ID: 5470)

• The only primary alcohol that can be prepared by the indirect hydration of alkene is ethyl alcohol
Answered by Payal Singh (May 24, 2017 5:32 p.m.)
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Why is some food left undigested?

Posted by Rachna gupta (May 24, 2017 2:27 p.m.) (Question ID: 5469)

• During digestion of food by products are formed that we can not digest.

Answered by Rachna gupta (May 25, 2017 2:37 p.m.)
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Why can't our body digests certain types of food?

Posted by Rachna gupta (May 24, 2017 2:26 p.m.) (Question ID: 5468)

• Humans cannot digest certain types of food because the appropriate enzymes to breakdown the molecules, are lacking in our body.

Answered by Payal Singh (May 24, 2017 2:36 p.m.)
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Why do we produce saliva when we see  food?

Posted by Rachna gupta (May 24, 2017 2:25 p.m.) (Question ID: 5467)

• The process of digestion starts in our mouth when we start chewing food(in most cases). Most of the saliva helps breakdown all the starch and other compounds to sugars.

So whenever you see and smell some delicious food your brain perceives you will eat it and hence asks the salivary glands to release the saliva in advance which we call mouth-watering.

Posted by Payal Singh (May 24, 2017 3:48 p.m.)
• But why is saliva produced when we see food?

Posted by Rachna gupta (May 24, 2017 3:39 p.m.)
• The process of digestion starts in our mouth when we start chewing food(in most cases). Most of the saliva helps breakdown all the starch and other compounds to sugars. So whenever you see and smell some delicious food your brain perceives you will eat it and hence asks the salivary glands to release the saliva in advance which we call mouth-watering.

Answered by Payal Singh (May 24, 2017 3:46 p.m.)
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Name any two pre colonial parts of India?

Posted by Priyanshu Nandan (May 24, 2017 2:24 p.m.) (Question ID: 5466)

• Ans. Three Indian ports of pre-colonial :

• Surat on the Gujarat coast
• Hoogly in Bengal
• Masulipatam on the coromandel coast
Answered by Naveen Sharma (May 24, 2017 2:39 p.m.)
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How come alimentary canal ( 9 metres ) can be longer than humans?

Posted by Rachna gupta (May 24, 2017 2:23 p.m.) (Question ID: 5465)

• Alimentary canal is longer but fits in our body as it is of different shapes and sizes at different levels.

Answered by Rachna gupta (May 25, 2017 2:38 p.m.)
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When did export of British cottons goods increase dramatically?

Posted by Priyanshu Nandan (May 24, 2017 2:22 p.m.) (Question ID: 5464)

• Ans. Exports of British cotton goods increased dramatically in the early nineteenth century. Produced by machines at lower costs, the imported cotton goods were so cheap that weavers could not easily compete with them. They were better in quality and cheaper in process than Indian textiles.

Answered by Naveen Sharma (May 24, 2017 2:30 p.m.)
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Name any two pre colonial parts of India?

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Posted by Priyanshu Nandan (May 24, 2017 2:06 p.m.) (Question ID: 5463)

• Ans. Three indian ports of pre-colonial :

• Surat on the Gujarat coast
• Hoogly in Bengal
• Masulipatam on the coromandel coast
Answered by Naveen Sharma (May 24, 2017 2:25 p.m.)
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• DNA-ase and RNA-ase are enzymes produced by....
• In case of taking food rich in lime juice, the action of ptylin on starch is.....
•  Fatty acids and glycerol are first absorbed by........
Posted by MUDASSIR MOHIUDDIN INAMDAR (May 24, 2017 2:06 p.m.) (Question ID: 5462)

• DNA-ase and RNA-ase are enzymes produced by Pancreas.
• In case of taking food rich in lime juice, the action of ptylin on starch is reduced
• Fatty acids and glycerol are first absorbed by lacteal
Answered by Payal Singh (May 24, 2017 2:23 p.m.)
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What is gestation?

Posted by SJ Jinsey (May 24, 2017 12:23 p.m.) (Question ID: 5461)

• Gestation is the process of development of fetus, beginning with fertilization and ending at birth. The duration of gestation period varies between species.

Answered by Payal Singh (May 24, 2017 12:38 p.m.)
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If a+b=5 and 3a+2b=20,  Then value of a+b is:

1) 10

2) 15

3) 20

4) 25

Posted by Sudhanshu Baranwal (May 24, 2017 10:39 a.m.) (Question ID: 5460)

• you have already given value of a+b = 5 then what is the use of asking.

it should be a printing mistake. you have to find value of 3a+b

Posted by Naveen Sharma (May 24, 2017 3:33 p.m.)
• Ooo.

But this ques. had come in chs exam

Answered by Sudhanshu Baranwal (May 24, 2017 2:56 p.m.)
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• Question Must be : If a + b = 5 and 3a + 2b = 20, then 3a + b will be

Ans. 4) 25

a + b = 5  .............(1)

3a +  2b =  20    .........(2)

From (1), a = 5 - b

put this value in (2), we get

=> 3( 5 - b ) + 2b = 20

=> 15 - 3b + 2b = 20

=> - b = 5

=> b = -5

put values of b in (1), we get

=> a - 5 = 5

=> a = 10

Now, 3a + b = 3(10 ) - 5

= 30 - 5 = 25

Answered by Naveen Sharma (May 24, 2017 11:55 a.m.)
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The original inhabitants of a country are called:

1)  residents

2) natives

3) aborigines

4) ancestors

Posted by Sudhanshu Baranwal (May 24, 2017 10:38 a.m.) (Question ID: 5459)

• 3) aborigines

Answered by Payal Singh (May 24, 2017 11:17 a.m.)
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Voltmeter has high resistance so that:

1) it takes large current from the circuit

2) it takes a negligible current from the circuit

3) it can be connected in series

4) none of these

Posted by Sudhanshu Baranwal (May 24, 2017 10:36 a.m.) (Question ID: 5458)

• 2) it takes a negligible current from the circuit

Answered by Payal Singh (May 24, 2017 11:18 a.m.)
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A 500 gm packet having volume 300 cm3 is placed in water  (density of water = 1gm/cm3).  The packet will:

1) float in water

2) sink in water

3) displace 500 gm water

4) displace 500 cm3 water.

Posted by Sudhanshu Baranwal (May 24, 2017 10:33 a.m.) (Question ID: 5457)

• 2) sink in water

Explanation : density of packet ={tex}Mass \over Volume {/tex}

{tex}500\over 300 {/tex}= 1.66 gm/cm3

It has higher density than water so it ll sink

Answered by Payal Singh (May 24, 2017 11:20 a.m.)
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Name the most dynamic industry of Britain in 18th- 19th century

Posted by Priyanshu Nandan (May 24, 2017 10:33 a.m.) (Question ID: 5456)

• Ans. The most dynamic industry of Britain in 18th- 19th century was Cotton and Metal Industry.

Answered by Naveen Sharma (May 24, 2017 11:14 a.m.)
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Write the name of the first symbol of new Era in England

Posted by Priyanshu Nandan (May 24, 2017 11:35 a.m.) (Question ID: 5454)

• Ans. Cotton was the first symbol of the new era (in britain). Until the 1840s, cotton was the leading sector in the first phase of industrialisation.

Answered by Naveen Sharma (May 24, 2017 11:34 a.m.)
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Describe the role of army in the early Roman empire.What was the policy of the roman emperors towarsds more expansionof the empire in the first two centuries?

Posted by Shreya Gaur (May 24, 2017 9:49 a.m.) (Question ID: 5453)

• Ans. Next to the emperor and the Senate, the other key institution of imperial rule was the army. Romans had a paid professional army where soldiers had to put in a minimum of 25 years of service. The army was the largest single organised body in the empire with 600,000 soldiers in the fourth century. The soldiers would constantly agitate for better wages and service conditions. These agitation often took the form of mutinies.

The emperor, the aristocracy and the army were the three main ‘players’in the political history of the empire. The success of individual emperors depended on their control of the army, and when the armies were divided, the result usually was civil war. Except for one notorious year (69 CE), when four emperors mounted the throne in quick succession, the first two centuries were free from civil war.

The emperor Augustus reigned from 27 BC to AD 14 with absolute power. He re-established political and social stability and launched two centuries of prosperity called the Roman Peace (Pax Romana). During the first two centuries Ad the empire flourished and added new territories as ancient Britain, Arabia, and Dacia (present-day Romania). People from the provinces streamed to Rome and became soldiers, bureaucrats, senators, and even emperors. Rome developed into the social, economic, cultural capital of the Mediterranean world. Most emperors ruled sensibly and competently till military and economic disasters brought on the political instability of the 3rd century AD.

Answered by Naveen Sharma (May 24, 2017 11:48 a.m.)
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What is meant by 'principate'in context of the roman empire ?What was the positon of of emperor and Senate in it?

Posted by Shreya Gaur (May 24, 2017 9:46 a.m.) (Question ID: 5452)

• Ans. The regime established by Augustus, the first emperor, in 27 BCE was called the ‘Principate’. Although Augustus was the sole ruler and the only real source of authority, the fiction was kept alive that he was actually only the ‘leading citizen’ not the absolute ruler. This was done out of respect for the Senate.

Senate was the body which had controlled Rome earlier, in the days when it was a Republic. The Senate had existed in Rome for centuries, and had been and remained a body representing the aristocracy, that is, the wealthiest families of Roman and later Italian descent mainly landowners.

Answered by Naveen Sharma (May 24, 2017 11:31 a.m.)
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What is osmosis?

Posted by Shubham Kardile (May 24, 2017 9:32 a.m.) (Question ID: 5451)

• Osmosis is a process in which the water molecules move from high concentration region to a low concentration region through a semi-permeable membrane.

Answered by Archith jayalal (May 24, 2017 7:30 p.m.)
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• Osmosis is the process in which water molecules moves from the region of high concentration to a region of low concentration through a semi permeable membrane.

Answered by Payal Singh (May 24, 2017 9:43 a.m.)
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An electric heater of resistance 8 Ohm draws 15Amp. from the service mains 2hrs. What will be the rate at which heat is developed in the heater ?

(If you feel some error in the question then please tell me because this is an NCERT question.)

Posted by Pranzal Kumar Sinha (May 24, 2017 9:08 a.m.) (Question ID: 5450)

Posted by Pranzal Kumar Sinha (May 24, 2017 9:33 a.m.)
• Ans. Given
Resistance of heater R = 8 Ohm

Current I = 15 A

Time = 2 Hours = {tex}2\times 3600 = 7200 \ s{/tex}

According to Joule's Law of Heating:

Heat  Generated H = {tex}I^2 .R. T{/tex}

Rate of Heat Generated =  {tex}H\over T{/tex} = {tex}{I^2.R.T\over T} = I^2.R{/tex}

{tex}(15)^2\times 8 = 225\times 8 = 1800 \ J/s{/tex}

Answered by Naveen Sharma (May 24, 2017 9:41 a.m.)
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How to find chemical reactants and products symbolically?

Posted by Murali Dharan (May 24, 2017 6:07 a.m.) (Question ID: 5449)

• 6CO+ 12H2O ----> C6H12O+ 6O2 + 6H2O

REACTANTS: CARBON DIOXIDE - CO2

WATER - H2

PRODUCTS: GLUCOSE - C6H12O6

OXYGEN - O2

WATER - H2O

Answered by Rachna gupta (May 25, 2017 2:48 p.m.)
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Convert into like decimal

(1).  6.5, 16.03

Posted by nitin garg (May 23, 2017 10:10 p.m.) (Question ID: 5448)

• We observe that in the given decimals 6.5, 16.03 the maximum number of decimal places is two.

The decimal 16.03 has the maximum number of decimal places, i.e., 2.

So, we convert each of the other decimal numbers into the one having two places of decimal.

So, 6.5 is written as 6.50

16.03 is already having two decimal places.

Therefore, 6.50, and 16.03 are expressed as like decimals.

Answered by Payal Singh (May 23, 2017 10:16 p.m.)
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Give me information about courseOf term1 or SA1

Posted by gaurav dhakad (May 23, 2017 9:38 p.m.) (Question ID: 5446)

• There will be no SA 1 this year. Syllabus for 1st exam will be decided by school.

Thank you.

Answered by Rachna gupta (May 25, 2017 2:50 p.m.)
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A wire's diameter is doubled. What will be the new resistance?

Posted by Pranzal Kumar Sinha (May 23, 2017 2:08 p.m.) (Question ID: 5445)

• Ans.

We know that

Resistance R = {tex}\rho {L\over A}{/tex}

Where {tex}\rho{/tex} is resistivity of material

L is length of wire

A is area of Cross-section of wire

Area A = {tex}\pi r^2{/tex}

If we double the Diameter it means radius is also doubled

So now Area = {tex}\pi (2r)^2= 4\pi r^2{/tex} = 4A

So  New Resistance R' = {tex}\rho {L\over 4A} = {R\over 4}{/tex}

Means new resistance will be {tex}({1\over 4})^{th}{/tex} of old resistance .

Answered by Naveen Sharma (May 23, 2017 2:55 p.m.)
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Why nitrogen is filled in  the  cyllinders of scuba divers if it blocks our capillaries.

Posted by Deepanshu Banga (May 23, 2017 12:18 p.m.) (Question ID: 5444)

The value of tan 90' is not defined  . Why ?

Posted by pritam mall (May 23, 2017 8:26 a.m.) (Question ID: 5443)

• Tangent of an angle is equal to the perpendicular divided by the base, As the angle approaches 90 degree, the value of the perpendicular starts to rise at abnormally higher rate but the value of the base remains same.

At 90 degree, there will be no triangle as the perpendicular and hypotenuse will never meet or meet at infinity and in that case perpendicular and the hypotenuse both wil be infinie..

tan 90 will be infinite

Answered by Payal Singh (May 23, 2017 8:35 a.m.)
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If cos (a+b)=0, then sin (a-b)=

1) cos 2b

2) cos b

3) sin 2a

4) sin a

Posted by Sudhanshu Baranwal (May 23, 2017 8:25 a.m.) (Question ID: 5442)

• 1) cos 2b

Explanation:

cos (a+b) =0

=> cos (a+b) = cos 90

=> a+b = 90

=> a = 90- b

Now

sin(a+b)

= sin(90-b-b)

= sin(90-2b)

= cos 2b     [as sin (90 - x) = cos  x]

Answered by Payal Singh (May 23, 2017 8:34 a.m.)
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