Students and Teachers Forum

1. 2 sina+cota-coseca=0

Here,  2sinA + cotA - cosecA = 0 or, 2sinA + cosA/sinA - 1/sinA = 0  [ Since, cotA = cosA/sinA , cosecA = 1/sinA.] or, 2sin2A + cosA - 1 = 0 or, 2(1 - cos2A) + cosA - 1 = 0    [ Sicne, sin2A = 1 - cos2A.] or, 2cos2A - cosA .....

2. In the number of two digits,square of sum of its digits is 49. If 23 is subtracted from three times the number, the digits are inversed.Find the number

Here is an example of same type. Look it arefully and try your question. Qustion: In a number of two digits the square of sum of its digits is 100. If 2 is .....

3. Write down the molecular formula and three uses of sodium carbonate.

The molecular formula of sodium carbonate is  Na2CO3. The main uses of sodium carbonate are  water softener  food processing aid  pH modifier  swimming pool .....

4. What is metabolism?

Metabolism is a biochemical process where the body uses to convert food into energy. These metabolic processes include breathing, eating and digesting .....

5. राष्ट्रपति मेरो कर्तव्य मा निबनध लेख । 

राष्ट्रप्रति मेरो कर्तव्य
केही महत्वपूर्ण बुँदा दिइएका छन्, .....

6. मेरो नेपाल

मेरो नेपाल
 नेपालको सामाजिक, सांस्कृतिक चिनारी .....

7.

Give the answer or choose the best alternatives:

Madrina. Anyone of them who ……….7……………. [is/am/are] keen to save my property can be given the rights to inherit them.” A week later, a cunning looking man from Madrina came to the court and said, “I am the best heir to her property, ………………….8………………… [amn’t I/ aren’t I/don’t I]? the judge said if it were him to decide, he ……..9……………. [will not give/would not give/would not have given] him any. The man was clearly upset. He said that the judge’s words had got him …………….10……….. [feel/felt/to feel] very sad.

7. is 8. aren't I? 9. would not give  10. to .....

8. Choose the best alternatives:
  

One evening as Jenny was returning home from work as she heard …………. [a/an/the] unusual cry from the corner of the street. Upon taking herself to the closer she saw an old lady lying unconscious. She had been robbed off by the gang of the street thugs. She looked pale and was bleeding from the injury of the head. “I must take her to the hospital or she will die …………… [with/of/in] the extreme pain and bleeding.” , she said. The old woman …….. [was taken/had taken/took] to the hospital. As she was being stretched towards the emergency, the attendant nurse asked her ……………… [where she had found her/ where she founds her/ where she finds her]. Jenny replied that she found her on her way home lying hopelessly on the roadside. “Please …………….. [save/saves/saved] this poor lady’s life,” Jenny begged. The doctor’s team tried their best to save the woman’s life ………………… [although/despite/ but] they failed.

It was later found that the old woman had nobody to inherit her vast fortunes. When the lawyer recovered her paper they were shocked.

 



 

10.  1. an  2. of  3. was taken  4. where she had found her  5. save 6. .....

9. Convert the following percentage into fraction with lowest terms. A) 55.5% b)2.275% c) 150% d) 375% e) 100% f) 20.5% g ) 250.75 h) 300.5% i) 250% j) 500%. Please do all question its important.

A) To convert percentage in to fraction, we divide the given percentage by 100. So,        55.5% = 55.5/100 = 555/1000    [ Since, revoming decimals from numerator by multiplying and dividing by 10.] = .....

10. What do you mean by the phrase that specifuc gravity of blood is ??

The specific gravity (relative density) of human whole blood and plasma from 25 healthy volunteers was determined gravimetrically. For whole blood it was found to be 1.0621 (95% confidence interval: 1.0652-1.0590) at 4°C and 1.0506 (95% .....

11. Find the value of x , y and z from the given figure.

Here, ∡OPN = 45o   [ Since diagonal of square bisects its angle and angle of square is 90o] z = ∡OPN = 45o.      [ As, PN//QR and corresponding angles.] In triangle ORQ,  ∡O + z =  y or, y = 90 .....

12. Find the hcf of: 4(x4 - 1), 6(x3 - x2 - x + 1).

Here,  First expression = 4(x4 - 1)  = 2.2{(x2)2 - 12} = 2.2(x2 + 1)(x2 - 12) = 2.2(x2 + 1)(x + 1)(x - 1) Second expression = 6(x3 - x2 - x + 1) = 2.3{x2(x - 1) - 1(x - 1)} = 2.3(x - 1)(x2 - .....

13. List any four uses of electricity in our daily life .

Electricity is important to run your appliances at home efficiently. For example Lighting TV  Refrigerator  Fan  electric .....

14. Rewrite the following sentence as indicated in the bracket.

We have already done our homework. (into negative)

We have not done our homework .....

15. The cost of 15m of clothes is Rs.1350.
a) Find the cost of 6m of clothes.
b) How many metres of clothes can be bought for Rs. 720 ?

Given, Cost of 15m clothes = Rs 1350 Cost of 1 m cloth = Rs 1350 / 15 = Rs 90 a) Cost of 6 m clothes = Rs 90 * 6 = Rs540 b) Metres of clothes that can be bought for Rs 720 = 720 / 90   = .....

16. Name three electrical devices which change the electrical energy into the heat energy ?

Examples of Electrical Energy to Thermal Energy Conversions:

1. A toaster draws electric current (electrical energy) from a wall outlet and converts these moving electric charges into heat (thermal energy) in the filaments that turn red hot to .....

17. ‘धनभन्दा विद्या ठूलो’ भन्ने विषयको विपक्षमा वादविवादः

धनको ठाउँमा विद्यालाई ठूलो बनाएर लेख्नुहोस् है त ।

‘धनभन्दा विद्या .....

18. X4-x, x2+ x+1

First expression = x4 - x =x(x3 - 13) Using formula of a3 - b3, we get = x(x - 1)(x2 + x + 1). Second expression = x2 + x + 1. Thus, HCF= common factors = x2 + x + .....

19. In which axis do the given points lie .Also show them in cartesian plane
a)( 0,7)
b) (-3,0)

a) (0, 7) lies on y-axis. b) (-3, 0) lies on .....

20. A cylinderical bucket having inner height and radius 32cm and 18cm respectively,is filled with sand. This bucket is emptid on a level ground and a conical heoped of sand formed. If height of the conical heap is 24cm find the radius and slant height of conical heap.

Now to find slant height (l) use the formula l2 = r2 + .....

21. Seven times a two digit number is equal to the four times the number formed by reversing the order of its digits. If  the difference between the digits is 3, find the origional number and show that difference between the number is nine times the difference betweeen the digits.

To solve it we have to let the no. be 10x+y. Now from the 1st case, 7(10x+y)=4(10y+x) or, 14x + 7y=40y + 4x or, 10x = 33y ..........................i) from the 2nd case, x - y = 3 or, x = 3 + y Using this value of x in (i), we get 30 + .....

22. Solve: cosa - sina =-1 (0

Here,  cosa - sina = -1 or, 1 + cosa = sina Squaring both sides we get (1 + cosa)2 = sin2a or, 1 + 2cosa + cos2a = 1 - cos2a or, 2cos2a + 2cosa = 0 or, 2cosa( cosa + 1) = 0 Either, 2cosa = 0 ⟹ cosa = 0 ⟹ a = 90o. Or, .....

23. Find the perimeter of a circle with radius 3.5 cm.

Here, radius = r = 3.5cm Perimeter = C = ? We know,  Perrimeter of circle = 2πr   =2 ⨯ 22/7 ⨯ 3.5cm = .....

24. निम्नलिखित हिसाब गरी दिनु होला सर ।

.....

25. Prove that:

cosec2a + cot4a = cota - cosec4a.

Here,  LHS = cosec2A + cot4A = 1/sin2A + cos4A/sin4A   [ Sicne,coesec = 1/sinand cot = cos/sin.] = 1/sin2A + (2cos22A - 1)/(2sin2A.cos2A)  .....

26. Prove that: (3 - 4sin2 θ).(sec2 θ - 4tan2 θ) = (3-tan2 θ) (1 - 4sin2 θ).

Here, LHS = (3-4sin2 θ) (1-3tan2 θ)

Break the tan into sin and cos and take L.C.M = (3-4sin2 θ) * (cos2 θ -3sin2 θ)/cos2 θ = .....

27. Solve: √3tanx - √2secx =1.

Here,  √3tanx - √2secx =1 Changing into sin and cos we get √3sinx - √2 = cosx or, √3sinx  = √2+ cosx Squarng both sides, we get 3sin2x = 2 + 2√2 cosx + cos2x  or, 3 - 3cos2x = .....

28. Write an essay on 'gender violence'.

Gender-based violence both reflects and reinforces inequities between men and women and compromises the health, self-respect, safety and sovereignty of its victims. It encompasses an extensive assortment of human .....

29. Write a short story with moral: Honesty is the best policy.

An honest boy  
Once there was a poor boy in a town, his father had died. He had a widowed mother and three younger sisters. But, there was no source of income to support .....

30. सविताको पर्यायवाची शब्द ................. हो । (सुर्य, चन्द्रमा, पृथ्वी)

.....

31. Solve: √2 cotx = cosecx  [ 0o ≤ x ≤ 360o.]

Here,  √2 cotx = cosecx or, √2 cosx/sinx  = 1/sinx  [ Since, cotx = cosx/sinx and cosecx = 1/sinx.] or, √2 cosx . sinx = sinx or, √2 cosx . sinx - sinx = 0 or, sinx(√2 cosx - 1) = .....

32. The total surface area and height of the given solid are 770cm2 and 14cm respectively, find the volume of the solid.

Here,      TSA = 770cm2 or, CSA of Hemi-sphere + CSA of cylinder + CSA Area of base = 770  or, 2πr2 +  2πrh  + πr2 = 770  or, 3πr2 + 2πr(14 - r) = 770     [ .....

33. राष्ट्रपति चुरे संरक्षण कार्यक्रमबारे प्रष्ट पार्नुहोस् ।

यस कार्यक्रमलाई आ.व. ०७०/०७१ मा राष्ट्रिय गौरवको आयोजनामा परिणत गरिएको थियो । यस क्षेत्रले .....

34. Cot3a=tan6a(0=360)

Here,   Cot3A = tan6A or, cot3A = cot(90o - 6A)    [ Since, tanX = cot(90 - X).] or, cot3A = 90o - 6A or, 3A + 6A = 90o or, 9A = 90o or, A = .....

35. What are the problems facing for the development of transport in Nepal? List in points.

The problems facing for the development of transportation are mentioned in the points below: - Geographically Nepal is a Himalayan country, due to this, the development of transportation is quite difficult. - There is a lack of skilled .....

36. Write an essay on Child Rights and Duties in about 200 words.

 Children should grow and develop all-round–physically, mentally, emotionally and socially. For this, proper care and facilities should be provided to them. Children need .....

37. Name the componnd formed by the chemical reaction between chlorine and potassium?

The chemical reaction between potassium and chlorine. 2K + Cl2 → 2KCl Potassium  + Chlorine → Potassium .....

38. Convert the word equation into balanced chemical equation calcium carbonate=calcium oxide +carbon dioxide

The word equation into a balanced chemical equation is CaCO3 → CaO + CO2 It is a decomposition .....

39. What are sub-atomic particles?

Subatomic particle, also called elementary particle, any of various self-contained units of matter or energy that are the fundamental constituents of all matter. Subatomic particles include electrons, the .....

40. Write the molecular formula of a compound formed by the combination of Na and O.

The molecular formula of the compound formed by the combination of Na and O.

4Na + O2 → 2Na2O (s)

Or

Na + O2 → NaO2 (s)

2Na + O2 → Na2O2 (s)

There are a lot of oxides of sodium and they are all .....

41. What does infinity stands for in terms of optics?

Infinity is not a number  It is just a concept.

We consider infinity that point from where light rays coming are parallel to principal axis of the lens or mirror.

We consider this point basically behind the centre of .....

42. When the object is placed at F the diverged ray will never meet than how the image will be formed?

.....

43. Mars is not suitable for survival even their is water and air. why?

The atmosphere of Mars is mostly carbon dioxide, the surface of the planet is too cold to sustain human life, and the planet’s gravity is a mere 38% of Earth’s. The atmosphere on Mars is equivalent to about 1% of the Earth’s .....

44. Find the lcm of m4+4 , m3-4m2+4m

Here,  First expression = m4 + 4 = (m2)2 + 2.m2.2 + 22 - 2.m2.2 = (m2 + .....

45. Prove that: cos4A + sin4A = 1/2 ( 2 - sin22A)

Here,  LHS = cos4A + sin4 .....

46. Prove that: 4sinA/2.cos3A/2 - 4cosA/2.sin3A/2 =  sin2A.

Here, LHS = 4sinA/2.cos3A/2 - 4cosA/2.sin3A/2 = 4sinA/2.cosA/2 ( cos2A/2 - sin2A/2) = 2(2sinA/2.cosA/2)(cosA)   [ Since,  cos2A/2 - sin2A/2  =cosA.] = 2 sinA.cosA   [ Since,  2sinA/2.cosA/2 = sinA] = .....

47. Prove that: cotπc/8 - tanπc/8 = 2.

Here,  LHS = cotπc/8 - tanπc/8   = cosπc/8 / sinπc/8  - sinπc/8 / cosπc/8 Taking LCM, we get = (cos2πc/8 - sin2πc/8) / (sinπc/8.cosπc/8) = 2 cos2πc/8 / .....

48. Prove that: sin5πc/7.sin2πc/7 - cos5πc/7.cos2πc/7 = 1

Here,  LHS = sin5πc/7.sin2πc/7 - cos5πc/7 cos2πc/7 = sin5πc/7 sin(7πc-5πc)/7 - cos5πc/7 cos(7πc/7- 5πc/7)  [ Since, 2π = 7π - .....

49. Prove that: cosπc/9 + cos5πc/9 +cos7πc/9 = 0

Here, LHS = cosπc/9 + (cos5πc/9 +cos7πc/9) = cosπc/9 + 2 cos(5πc/9 +7πc/9)/2 . cos(5πc/9 -7πc/9)/2   [ Since,CosC + CosD = 2Cos[(C+D)/2]Cos[(C-D)/2].] = cosπc/9 + 2 cos(5πc/9 +7πc/9)/2 . .....

50. Prove that: tan235o = 2tan200 + tan215o.

Here, tan235o = 2tan200 + tan215 or, tan(180 + 55o) = 2tan(180+20) + tan(180+ 35) or, tan55 = 2tan20 + tan35.   [ Since, tan(180 - A) - tanA.] To prove it we have to use tan(A+B) formula, We know, 55 = 20 + .....