Students and Teachers Forum

1. Soap is not suitable to wash clothes with hard water. Justify this statement giving three reasons.

Soaps are not suitable for washing clothes when water is hard. Soaps, when used with hard water, does not lather or produce foam easily because of the formation of a curdy precipitate or scum. This scum is created when soaps react with .....

2. Solve by factorization method: 5x2 - 2x - 3=0

5x2 - 2x - 3 = 0 or, 5x2 - (5 - 3)x - 3 = 0 or, 5x2 - 5x + 3x - 3 = 0  or, 5x(x - 1) + 3 (x - 1) = 0 or, (x - 1) (5x + 3) = 0 Can you solve .....

3. If you were the vice commissioner of CIAA prepare a list of any four functions that you consider to reduce corruption from the country.

Well, If I were the Vice-Commissioner of Communication of the Investigation of Abuse of Authority, I would give prime focus to the following four functions: a) I would develop the institutional capacity of the CIAA. b) I would coordinate with the .....

4. State any four achievements of Bay of Bengal Initiative for Multi-sectoral Technical and Economic Cooperation (BIMSTEC) summit held in Nepal.

The achievements of 4th BIMSTECT Summit were as follows: - Institutional Reform will be made. - Poverty Alleviation will be given a prime focus. - Transport and Communication will be extended in the BIMSTECT region. - Trade an Investment will be .....

5. How does a person transform into social being from biological being?

Definitely, a person is a biological creature by birth. This biological creature is changed into a social being through socialization. The humans are not different than an animal at the time of birth. Later when they are socialized, they .....

6. A man fixed 150 kg of rice worth Rs.15 per kg and 3 quital at Rs.18 per kg. What is the selling price of mixture per kg if he makes 10 percent profit in all?

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7. A man sells two books at Rs.3920 each. If he maks 10 percent profit in first and 10 percent loss in second. Find the profit or loss percent.

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8. The priceof copy falls down by 20 percent so that hari can buy 25 copy more then total amount is 4000 . Find the cp of each copy.

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9. If Sn = n + 1, find a4 where Sn is sum of nth terms and an is nth term of a sequence.

Here,  Sn = n + 1. Now, Put n = 4,  S4 = 4 + 1 = 5 Put n = 3, S3 = 3 + 1 = 4. We know,  .....

10. Show the nth term of the series -3 5+ 46- 57+ 68-79 in sigma notation.

Here,  t1 = -3/5= (-1)1 (2  + 1) /(4 + 1) t2 = 4/6= (-1)2 (2 + 2) /(4 + 2) t3 = -5/7= (-1)3 (2 + 3) /(4 + 3) Replace 3 by n,  tn = (-1)n (2 + n) /(4 + n) Writting .....

11. If a1, a2, a3 ... are the terms of a sequence such that an = an- 1an- 2 where a1 = 1, a2 = 2, find a5.

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12. Write the condition required for metrix multiplication.

In order for matrix multiplication , the number of columns in the first matrix must be equal to the number of rows in the second matrix. Example:  So, it follows that in order for matrix .....

13. If A 41-12 show that  6A- A2

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14. Prove that :sin80+sin10cos⁡10-cos⁡80=cot⁡35

Here,  LHS  = (sin80o + sin10o)/(cos10o - cos80o)  Using formula SinC + SinD = 2Sin[(C+D)/2]Cos[(C-D)/2] and CosC - CosD = 2Sin[(C+D)/2]Sin[(D-C)/2]  .....

15. Prove that: cotA/2 - tanA/2 = 2cotA.

Here,  LHS = cotA/2 - tanA/2 Changing cot and tan in sin & cos we get, = cosA/2 / sinA/2 - sinA/2 / cosA/2 Taking LCM, we get = (cos2A/2 - .....

16. Prove that: cosecA - cotA = tanA/2.

Here,  LHS = cosecA - cotA Changing them in to sin & cos, we get = 1/sinA - cosA/sinA = (1 - cosA)/sinA = (1 - 1 + 2sin2A/2)/ sinA   [ .....

17. Prove that: cosA/(1 - sinA) = tan(πc/4 +A/2).

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18. √{(1 + sinA)/(1 - sinA)} = tan(45o + A/2).

Here, LHS = √{(1 + sinA)/(1 - sinA)} = √{(1 + sinA)(1 + sinA)/(1 - sinA)(1 +sinA)} = √{(1 + sinA)2/(12 - sin2A)} = √{(1 + sinA)2/cos2A} =  (1 + .....

19. Find the equations of the line which is perpendicular to the line 7x-5y-6=0 and passing through the point (-1,-2)

The slope of the line 7x - 5y - 6 = 0 is, Slope = m1 = -coeff. of x  /coeff.of y  = -7 / .....

20. इश्वरको पर्यायवाची शब्द ---------होइन। (सुर , मन्दिर ,भगवान )

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21. Rewrite the following sentences s indicated in the brackets.

She said,"I had cooked."(into indirect speech)

She said that she had .....

22. लालीगुराँसको बारेमा निबन्ध लेख्नुहोस । 

लालीगुराँसः निबन्ध
लालीगुराँस नेपालको राष्ट्रिय .....

23. Prove that:
( cot2a.cot2b-1 ) / ( cot2b-cot2a ) = cot(a+b).cot(a-b)

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24. Complete the given task.

She asked me if I was going with them. Or she asked them if I was coming with them. ( into direct speech)

She said to me, Are you going with them?"                                      or She said to them, "Am I going with .....

25. Complete the given task.

It was a great sight. ( change into interrogative)

Was it a great sight?  or  How was a .....

26. Change the sentence as directed in brackets.

1.Manjila threw a tantrum when she was told that she wouldn't be able to go. (into negative sentence)

2. The boy did not kill the spider with issue. (into positive sentence)

3. The angry mother asked her son if he thought that he knew better than his dad. (into direct speech)

4. Where have you been found by your father? (into active voice)

5. We shall forget these happy moments. (into simple past tense)

6. There won't be any trouble, ...........................? (a question tag)

1 . Manjila threw a tantrum when she was told that she wouldn't be able to go. (into a negative sentence) Ans. Manjila did not throw a tantrum when she was told that she wouldn't be able to go. 2. The boy did not kill the spider with issue .....

27. What is osteocytes?

Osteocyte, a cell that lies within the substance of fully formed bone. It occupies a small chamber called a lacuna, which is contained in the calcified matrix of bone. Osteocytes derive from osteoblasts, or bone-forming cells, .....

28. If f(x) = x2 - 4x + 2 and g(x) = 3x2 + 3. Find f(x).g(x) - ( 2x + 2 ).

Here,  f(x) = x2 - 4x + 2 and g(x) = 3x2 + 3 So,  f(x) . g(x) = ( x2 - 4x + .....

29. Show that the points (5,-2) and (7,4) and (6,1) are collinear.

Here, A( 5,-2 ), B( 7,4 ) and C( 6,1 ) Using formula for slope between AB, m1 = [ 4 - (-2 ) ] / ( 7 - 5 ) = ( 4 + 2 ) / 2 = 6 / 2 = 3 Again, Using formula for slope between BC, m2 = ( 1 - 4 ) / ( 6 - 7 ) = -3 / -1 = 3 Since, m1 = m2, .....

30. The marked price of an article is Rs.20000 and the shopkeeper allows 10% discount after leying VAT if a customer pays it Rs.2034. What percent of VAT was charged ?

Given, MP of the article = Rs 20000 Discount percent = 10% VAT amount = Rs 2034 Let VAT percent be x. Using formula, Discount amount = Discount % of MP = 10% of 20000 = Rs 2000 Again, SP = MP - Discount amount = 20000 - 2000 = Rs 18000 Again, VAT .....

31. what is a consonant? 

The 21 consonant letters in the English alphabet are B, C, D, F, G, H, J, K, L, M, N, P, Q, R, S, T, V, W, X, Y, .....

32. Find the value of :
146 × 155356  × 65

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33. Why is unemployment increasing in Nepal?

- political instability which has directly affect the pace of development, - lack of industrial growth and development, - lack of skilled manpower, - lack of the growth of private sectors, - lack of dignity of .....

34. Show the difference between skilled and semi-skilled professional.

The difference between skilled and unskilled manpower is shown in the table below: Skilled Manpower Unskilled Manpower They have specialized training or a learned skill-set to perform the work.  They have less .....

35. In democracy the majority is valued but minority should also be respected. Justify

And the opinion of the minority is also be respected and should be respected.  Why because democracy is the system of equal participation to each and every people. It equally requires the fulfillment of the rights of the minority. The .....

36. If Sn=2n2+3n, find t10.

Given, Sn = 2n2 + 3n S10 = 2*102 + 3*10 = 2*100 + 30 = 200 + 30 = 230 S9 = 2*92 + 3*9 = 2*81 + 27 = 162 + 27 = 189 We know, t10 = S10 - S9 = 230 - 189 = .....

37. Write a short note on:  Status of population composition by occupation in Nepal

Nepal is a developing country. It has not been able to manufacture much industrial goods. Manufacturing is still at the developmental stage. lt represents less than 10% of the GDP. There has been significant decrease in agricultural sector while .....

38. a) How is ceramic produced?

b) Why is sodium silicate glass often called water glass?

c) How is ordinary glass made? Write its uses?

d) Accurate volume measuring devices are generally made from borosilicate glass. Why?

e) What is the common name of  borosilicate glass? Give two reason why laboratory equipments are usually made from borosilicate glass.

b) Water glass is the common name for an aqueous solution of either sodium silicateor potassium silicate.     It's also called “liquid glass”.     It gets its name because .....

39. Ammonia is manufactured by Haber's process

a) Under what conditions do the reactants combine to form ammonia? Give a balanced equation for the reaction.

b) In what ratio by volume, are the above gases used?

c) State one possible source of each reactant used in haber's process.

d) Write the function of finely divided iron and molybdenum in the Haber's process?
 

b) Nitrogen and hydrogen are used in 1 :3 .....

40. What happens when

a) carbon dioxide dissolves in water?
b) calcium bicarbonate is heated?
c) carbon dioxide gas is passed for short time in a jar containing limewater?
d) carbon dioxide gas ia passed for a long time in a jar containing limewater?
e) charcoal burns in air?
f) a red hot coke is reacted with carbon dioxide at 900C?
g) few drops of sodium hydroxide is added in a test tube containing carbon dioxide and  introduce in a vessel having water?
h) a glass rod dipped in hydrochloric acid is introduced ina jar containing  ammonia gas?
i) ammonia reacts with sulphuiric acid?
j) ammonia reacts with carbon dioxide at high temperature and low pressure?

e)  Since charcoal is mainly carbon and interacts with oxygen the end result is mainly CO2 ,carbon dioxide.       Unfortunately, if you burn charcoal in an oxygen deficient atmosphere you can get .....

41. Who is the main narrator of the story?

The main narrator of the story is the time traveller's dinner .....

42. How did these little people treat him?

The little people treated him by welcoming him with garland and flowers. They led the time traveller to the nearest .....

43. Why did the Time Traveller feel that he had created the time machine in vain?
 

Time Traveller felt that he had created the time machine in vain because he believed that the future generation would be smart but rather their intelligence was that of a five years old .....

44. Prove that the equation ax2 +2h xy+by2 always represent a pair of straight lines passing through the origin.

Thus, the equation ax2 +2h xy+by2 always represent a pair of straight lines passing through the .....

45. Find the equation of circle centre at (-1,2) and passing through the centre of circle whose equation is x2+y2+6x-4y-8=0

Here, centre of the required circle is (h, k)= (-1, 2). To find the centre of the given circle x2+y2+6x-4y-8=0 Compare it with x2 .....

46. Can you describe his journey through time?

Answer the followign question.

a) Why didn't the guest believe in the time machine?

b) Canyou describe his journey through time?

c) Describe the place and the people he met there when he travelled

His journey was quite unpleasant. The twinkling succession of darkness and light was quite unpleasant to his eyes. In the darkness, he saw the moon spinning swiftly through quarters from new to full. He also saw brilliant arch rising which was more .....

47. Why didn't the guests believe in the machine?
 

The guest did not believe in the time machine because the time traveller was too clever to be .....

48.  If f(x) = ax +b,  f(4) = 11 and f(5) = 13, find the value of a & b.

Here is same question. Please replece m by a and c by b and try your question. Question: If f(x) = mx +c,  f(4) = 11 and f(5) = 13, find the value of m & .....

49. If f(x+2) = 3x +1 find the  f(x) anf f(1).

Here, f(x+2) = 3x + 1 Put, x  = x - 2  we get      f(x - 2 +2) = 3(x + 2) + 1 or, f(x) = 3x + 7. Put x = 1, we get f(1) = 3 .....

50. 3.If f(x) = x3 - 1/x3 prove that f(3a) + f(1/3a) = 0.

Here, f(x+3)=f(x)+f(3) Put x = 0, we  f(0+3)=f(0)+f(3) or, f(3)=f(0)+f(3) or, f(0)=0.................(i) Porved. Again, put x = -  3, f(-3+3)=f(-3)+f(3) or, f(0)=f(-3)+f(3) or, 0 = f(-3) + f(3)   [ Since, .....