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Why structural isomerism is not possible for propane?

Posted by gaurav deokar (Feb 22, 2017 12:43 p.m.) (Question ID: 2442)

Show that T, T, T, .... T.... form an AP where Tis defined as: T= 9 - 5n. Also find the sum of the first 15 terms.

Posted by satvik Kumar (Feb 22, 2017 12:04 p.m.) (Question ID: 2440)

• We have to prove something also

Posted by satvik Kumar (Feb 22, 2017 12:47 p.m.)
• Please read the question carefully.. Question also says that Show that T1 , T2 , T3 , .... Tn .... form an AP where Tn is defined as: Tn = 9 - 5n

Posted by satvik Kumar (Feb 22, 2017 12:46 p.m.)
• Just calculate the 1st 3 or 4 terms & show the constant common difference.

T1 = 9 - 5 = 4

T2  = 9 - 10 = -1

T3 = 9 - 15 = -6

T = 9 - 20 = -11

Now, if one checks the difference in any of the consecutive terms, it is -5 which is constant number.

Also, Tn = 9 - 5n (given) => Tn-1 = 9 - 5(n - 1)

Further, Tn  - Tn-1  = (9 - 5n) - {9 - 5(n - 1)}

= 9 - 5n - (9 - 5n + 5) = 9 - 5n - 9 + 5n - 5 = - 5 (Common Difference between any 2 consecutive terms for any value of n)

Hence, one can say that it is forming an AP.

Answered by Manish Gandhi (Feb 22, 2017 1:38 p.m.)
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• Given:     Tn = 9 - 5n

T1 = a = 9 - 5 x 1 = 9 - 5 = 4

T2 = 9 - 5 x 2 = 9 - 10 = -1

Therefore, d = -1 - 4 = -5

S15 = n/2[2a + (n - 1)d]

= 15/2[2 x 4 + (15 - 1) x (-5)]

= 15/2[8 - 70]

= 15/2 x [-62]

= -465

Therefore, the sum of 15 terms of given AP is -465.

Answered by Rashmi Bajpayee (Feb 22, 2017 12:30 p.m.)
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If the ratio of sum of the first n terms of  an a.p is  m: n2, show that the ratio of its mth  and nth term is   (2m-1 ) :  (2n-1)....

Posted by Ranveer Raj (Feb 21, 2017 11:37 p.m.) (Question ID: 2424)

• Ans. Let First Term of AP = a

Common Difference = d

Then

$$S_m = {m\over 2} [{2a+(m-1)d}]$$

And

$$S_n = {n\over 2} [{2a+(n-1)d}]$$

=> $${S_m\over S_n} = { m^2\over n^2}$$

=> $${2m [2a+(m-1)d] \over 2n[2a+(n-1)d]} = {m^2\over n^2}$$

=> $${ [2a+(m-1)d] \over [2a+(n-1)d]} = {m\over n}$$

=> $$2an+mnd - nd = 2am+ mnd -md$$

=> $$2an-2am = nd -md$$

=> $$2a(n-m) = (n -m)d$$

=> 2a = d       ......(1)

=> $${a_m\over a_n} ={ a+(m-1)d \over a+(n-1)d}$$

=> $${a_m\over a_n} ={ a+(m-1)2a\over a+(n-1)2a}$$

=> $${a_m\over a_n} ={ 2m-1\over 2n-1}$$

Hence Proved

Answered by Naveen Sharma (Feb 22, 2017 8:41 a.m.)
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If fand f2 are focal length of two lens,what is the relation for equivalent focal length?

Posted by Ranveer Raj (Feb 21, 2017 11:30 p.m.) (Question ID: 2423)

If angle of incidence=90, then angle of refraction=?

Posted by Ranveer Raj (Feb 21, 2017 11:24 p.m.) (Question ID: 2422)

• To answer this, one must know the mediums of incidence & refraction. then the below formula can be used:

<i>n1 * sin A = n2 * sin B</i>

where A is the angle of Incidence & B is the angle of Refration. Also, n1 is the index of refraction for the material the incident light ray is traveling through, and n2 is the index of refraction for the material the refracted light ray is traveling through.

Answered by Manish Gandhi (Feb 22, 2017 12:38 p.m.)
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Acc. To snells law- n21 xn12=?

Posted by Ranveer Raj (Feb 21, 2017 11:21 p.m.) (Question ID: 2421)

• Acc. To snells law- n21 xn12= 1 (Answer)

Answered by Manish Gandhi (Feb 22, 2017 12:39 p.m.)
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Formula of vinyl chloride?

Posted by Ranveer Raj (Feb 21, 2017 11:17 p.m.) (Question ID: 2420)

• And. C2H3Cl

Answered by Naveen Sharma (Feb 22, 2017 8:43 a.m.)
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Homologous organ ?

Posted by Ranveer Raj (Feb 21, 2017 10:18 p.m.) (Question ID: 2417)

• The organs which perform different functions in different species but have similar basic structure and similar embryonic origin are called homologous organs.

For eg -  1. Forelimbs of frog, lizard, humans, birds,  etc.

Answered by Shruti Sharma (Feb 22, 2017 1:29 p.m.)
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• The arm of a human, the wing of a bird or a bat, the leg of a dog and the flipper of a dolphin or whale are homologous structures. They are different and have a different purpose, but they are similar and share common traits.

Answered by Shweta Gulati (Feb 21, 2017 10:25 p.m.)
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What is a covalent bond?

Posted by Ranveer Raj (Feb 21, 2017 10:14 p.m.) (Question ID: 2416)

• The sharing of electrons by an atom to complete its electronic configuration leads to the formation of covalent bonds. Example carbon forms covalent bonds.

Answered by Shweta Gulati (Feb 21, 2017 10:27 p.m.)
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A circuit has fuse of 5A. What us the maximum number of 100W bulbs that can be safely used in circuit?

Posted by Krishna Sinha (Feb 21, 2017 6:53 p.m.) (Question ID: 2404)

• Suppose x number of such bulbs can be used

Power of one bulb = 100 watt

Power of x bulbs (p) = 100 X x watts

Potential difference (V) = 220 volts

I = 5 ampere

We know that P = VI

100 X x = 220 x 5

x = 220 x 5 /100 = 11 bulbs.

Answered by Shweta Gulati (Feb 21, 2017 7:43 p.m.)
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For an AP Sm=20 and Sn=10 and n-m=1,then prove that n=10÷a where a=d.

Posted by Sagar Maheshwari (Feb 21, 2017 11:49 a.m.) (Question ID: 2392)

• $$I \space think \space in \space question S_m = 10 \space and \space S_n = 20$$

Ans. Given : $$S_m = 10$$

$$S_n = 20 \space \space \space \space ..... (1)$$

=> n-m = 1

=> m = n-1

The sum of m terms i.e (n-1) terms

$$S_{n-1} =S_m = 10 \space \space \space \space \space \space ...... (2)$$

=> $$n^{th} term = S_n - S_{n-1}$$

=>$$n^{th} term = 20 - 10 = 10$$

=> $$a + (n-1)d = 10$$

=> $$a + (n-1)a = 10 \space \space \space \space \space [as \space a =d ]$$

=> $$a+ na -a = 10$$

=> $$na = 10$$

=> $$n = {10\over a}$$

Hence proved

Answered by Naveen Sharma (Feb 21, 2017 12:42 p.m.)
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How to improve my minor mistake in maths.

Posted by Rockstar Aadi (Feb 21, 2017 6:33 a.m.) (Question ID: 2379)

• Work without tension. Enjoy doing maths. Never think it as meri attma hamesha satayegee. Best of luck.

Answered by Amrit Joseph (Feb 21, 2017 10:05 p.m.)
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• Practice maths for 3 hours daily with full concentration

Answered by pranjal boora (Feb 21, 2017 9:34 a.m.)
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Blind spot

Posted by Sandeep Kumar (Feb 20, 2017 8:18 p.m.) (Question ID: 2369)

Posted by JD Shukla (Feb 20, 2017 9:07 p.m.)
• Ans.The blind spot is the area on the retina without receptors that respond to light. Therefore an image that falls on this region will NOT be seen. It is in this region that the optic nerve exits the eye on its way to the brain.

Answered by Naveen Sharma (Feb 20, 2017 9:31 p.m.)
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A three times magnified image of a candle flame is to be projected on a wall which type of lens required for this purpose if the candle is at a distance of 6m from the wall calculate the focal length of the lens

Posted by Simran Singhania (Feb 20, 2017 4:54 p.m.) (Question ID: 2363)

• m = v/u

3 = 6/u

u = 2

By lens formula

1/u - 1/v = 1/f

1/2 - 1/6 = 1/f

3 - 2/6 = 1/f

1/6 = 1/f

f = 6 cm

Answered by Shagun Vishwakarma (Feb 20, 2017 7:22 p.m.)
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naubat khane Mein Ibadat part May Sandesh likhiye

Posted by ambika singh (Feb 20, 2017 9:21 a.m.) (Question ID: 2351)

Write causes of Bolivian water War?

Posted by Aslam Pathan (Feb 19, 2017 8:09 p.m.) (Question ID: 2340)

• Bolivia is a poor country.The UN forced it's government to give up its control over water supplies
• The rights over water supply was sold to  an MNC by government for a city of Cochabamba.The MNC increased the price of water
• Most of the people got the bill of about Rs1000 and there average income of people is Rs 5000.Thus this led to simultaneous revolt by people.This led to Bolivian Water War
Answered by ashita singh (Feb 20, 2017 6:21 a.m.)
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Which enzyme helps in breaking surcose into glucose and fructose?

Posted by Sarthak Chauhan (Feb 19, 2017 6:56 p.m.) (Question ID: 2337)

• The enzyme sucrase digests sucrose or table sugar into its constituent units of glucose and fructose, while lactase breaks lactose or milk sugar into glucose and galactose. These monosaccharides are absorbed in the small intestine and transported to the liver through blood.

Answered by Shweta Gulati (Feb 20, 2017 1:06 a.m.)
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• Invertase

Answered by sunny dhankhar (Feb 19, 2017 10:02 p.m.)
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The radii of circular ends of a bucket are 5.5  cm and 15.5 cm and its height is 24 cm. Find the surface area of the bucket.

Posted by Shruti Sharma (Feb 19, 2017 5:37 p.m.) (Question ID: 2336)

• Slant height (l) = {h2 + (R - r)2)}1/2

= {242 + (15.5 - 5.5)2 }1/2

= {576 + 100}1/2

= 26 cm

CSA of bucket = πl(R + r) + πr2

= 22/7{26(15.5 + 5.5) + (5.5)2}

= 22/7{30.25 + 546}

= 22/7 × 576.35

= 1811.07 sq. cm

Answered by Rashmi Bajpayee (Feb 19, 2017 6:12 p.m.)
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Q)What is the difference between regeneration and fragmentation?

Posted by PRANTIK SAHA (Feb 19, 2017 2:01 p.m.) (Question ID: 2331)

•  Fragmentation Regeneration 1. Fragmentation occurs in multi-cellular organisms with simple body organisation. 1. Regeneration occurs in fully differentiated multi-cellular organisms with complex body organization. 2. In fragmentation, an organism breaks into pieces and each piece develops into new individual. 2. In regeneration organisms if breaks into pieces, each piece may or may not develop into new individual. 3. No specialised cells are involved in fragmentation. 3. In regeneration, specialised cells proliferate and form a mass of cells. The cells from the mass differentiate to form different cells types and tissues. Example: Spirogyra Example: Regeneration of blood cells in mammals.
Answered by Sarthak Chauhan (Feb 19, 2017 6:40 p.m.)
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For external boards will our sa1 result affect our sa2 result for the final cgpa?  Sa1 marks will be added to our sa2 marks to get the final cgpa??

Posted by Jagriti Khanna (Feb 19, 2017 12:02 p.m.) (Question ID: 2327)

• So then if I got a cgpa of 8.6 in the first term can I get a 10cgpa in the final result?

Posted by Jagriti Khanna (Feb 21, 2017 10:46 p.m.)
• Yes , sa 1 is important .

If you want to get good cgpa then you have tobringo

Answered by Uditkumar Swami (Feb 19, 2017 5:57 p.m.)
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what was the composition of agent orange poison?

Posted by Vishu Tomar (Feb 19, 2017 9:58 a.m.) (Question ID: 2322)

• Ans. It was a 50/50 mixture of two herbicides: 2,4-D and 2,4,5-T

Answered by Naveen Sharma (Feb 19, 2017 8:30 p.m.)
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Write a letter to principal to issue a library book until the exam

Posted by Kishore Mali (Feb 19, 2017 8:26 a.m.) (Question ID: 2319)

The perimeter of a sector of a circle of radius 5.2 cm is 16.4 cm.find the area of a circle.

Posted by John Dungdung (Feb 19, 2017 7:32 a.m.) (Question ID: 2317)

Posted by Rashmi Bajpayee (Feb 19, 2017 3:57 p.m.)

The sum of the number and its reciprocal is 2 ×1/30.find the number

Posted by John Dungdung (Feb 19, 2017 7:28 a.m.) (Question ID: 2316)

Coal on burning prodces heat and energy but when we eat it then we dont get energy,but we eat an apple then we will get energy.why?

Posted by Piyush Dubey (Feb 19, 2017 7:14 a.m.) (Question ID: 2315)

• Because our bile is not so strong that it can digest coal and get energy from it. Also coal has no glucose and we take glucose as energy.

Answered by Vishu Tomar (Feb 19, 2017 10:03 a.m.)
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what is 8/15 of an hour ( in minutes )

Posted by Jithin Joseph (Feb 18, 2017 11:34 p.m.) (Question ID: 2310)

• 8/15 of an hour

= 8/15 of 60 min

= 8/15 × 16 min

= 8 × 4 min

= 32 minutes

Answered by Rashmi Bajpayee (Feb 19, 2017 4:03 p.m.)
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• 32minuts

Answered by Sakshi Gupta (Feb 18, 2017 11:39 p.m.)
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why human eye is able to see the 3d objects ?

Posted by Abhishek Kapoor (Feb 18, 2017 7:08 p.m.) (Question ID: 2298)

• Human eye is able to see the 3-D objets due to double eyes that can see objects with two differnet angles.

Answered by RAJENDRA SINGH (Feb 18, 2017 9:25 p.m.)
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why rainbow is curve?

Posted by Abhishek Kapoor (Feb 18, 2017 7:07 p.m.) (Question ID: 2297)

• Rainbow is curved as horizon appears curved and dispesed light enters the eyes after total internal reflection.

Answered by RAJENDRA SINGH (Feb 18, 2017 9:29 p.m.)
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If 3+5+7+........ to n terms/ 5+8+11+.........to 10 terms = 7. Find 'n' ?

Posted by Harmehar Malhotra (Feb 18, 2017 4:48 p.m.) (Question ID: 2291)

• Both the numerator and denominator are the sums of two series up to 'n' terms:-

Since the sum = (n/2)(2a+(n-1)d)

For series in the numerator :-

a=3, d=2, n=n

Therefore numerator = (n/2)*(6+(n-1)2) = (n/2)*(2n+4)

And for the denominator series:-

a=5, d=3, n=10

Therefore denominator = (10/2)*(10+(10-1)3) = (n/2)*(3n+7) = 185

Therefore Acc. to question:-

(n/2)*(2n+4) / (185)   = 7

= n2 +2n- 1295 = 0

= n2 + 37n - 35n - 1295 = 0

=n=35 ( Since ncan not be equal to 37)

Answered by Devanshu Agarwal (Feb 18, 2017 6:26 p.m.)
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"Punishment does catch up with the sinner although it may be delayed
sometimes‘.
Comment on this statement with the reference to the poem the rime of the ancient mariner.

Posted by Dibyansika Biswal (Feb 18, 2017 1:27 p.m.) (Question ID: 2285)

• i dont know

Answered by Zaheen Mohammed (Feb 18, 2017 2:12 p.m.)
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