Students and Teacher's Forum

Students and Teachers Forum

1. l₁ and l₂ two axes of reflections intersecting at the origin O and inclined with each other at an angle of 45^o.Find the image of the point (-5,-3) and (4,-2) by the reflection about the l₁ followed by the reflection about the line l₂.

P(-5, -3)---------------90o rotation----------->P'(3 , - 5) Similarly do for next point (4, .....

2. If we make a chemical reaction between nitrogen and hydrogen what will we get?

Nitrogen gas (N2) reacts with hydrogen gas (H2) to form ammonia (NH3). N2 + H2 → .....

3. The square matrix A is said to be idempotent if A² = A. If A = 21-2-1

, prove that matrix A is idempotent.

Here, A = 21-2-1 Now, A2 = A.A = 21-2-1.21-2-1 = 2⨯2 + (1⨯-2)2⨯1+1⨯-1-2⨯2+(-1⨯-2)-2⨯1+(-1)⨯(-1) = 4-22-1-4+2-2+1 = .....

4. If x+k is a factor of x²-5x +6, find the value of k

Here, x + k is factor of x2 - 5x + 6 So, by factor theorem, f(-k) = 0 or, (-k)2 - 5(-k) + 6 = 0 or, k2 + 5k + 6 = 0 or, k2 + 3k + 2k + 6= 0 Now factorize and find .....

5. Define composite function of two functions. If f(x) = 2x and g(x) = x + 2, find the composite of the functions f and g.

Here, f(x) = 2x & g(x) = x + 2. Now composite function of f & g is, fog(x) = f{g(x)} = f(x + 2) = 2( x + 2) .....

6. What is optical density?

“The optical density of a material is a logarithmic ratio of the falling radiation to the transmitted radiation through a material. It is also referred as a fraction of absorbed radiation at a particular wavelength.” The medium’s .....

7. Do the sun rays refract when they enter the earth's atmosphere? Justify.

We know that air gets a bend in presence of air. But in space, there is no air so light doesn't get bend when the light ray enters the earth atmosphere if get .....

8. Refractive index has no unit. Why?

This is because the refractive index is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium . As it is a ratio it is unitless . The units m/s or km/h cancel out each .....

9. Solve:
z³ - 19z + 30 = 0

Let, f(z) = z³ - 19z + 30 = 0 Here, factors of constant term 30 are ±1, ±2, ±3, ±5 ,±6, ±10, ±15 ±30. When z = 3 f(2) = 33 - 19 ⨯ 3 .....

10. Priya have rupees 10 less then two times of supriya. If priya have rs.75 in her pocket. How much did supriya have?

Here, Supriya have Rs.x . Then 2x - 10 = 75 or, 2x = 75 + 10 or, 2x = 85 Solve and find .....

11. Solve by matrix method : ( 3x + 5y)/4 = ( 7x + 3y) / 5 = 4.

Here, we have given ( 3x + 5y)/4 = ( 7x + 3y) / 5 = 4. Taking first and last ratios, we get ( 3x + 5y)/4= 4 ⟹ 3x + 5y = 16 ...................(i) Taking second and last ratios, we get ( 7x + 3y)/5= 4 ⟹ 7x + 3y = .....

12. Rationalize the denominator of:

√2/(√3 - √5 - √2)

Here, we need to rationalize the denominator (i,e; remove the irrational from the denominator) of √2/(√3 - √5 - √2). Multiply numerator and denominator by (√3 - √5 + √2) we .....

13. Write advantages and disadvantages of federal system in a tabular form.

The advantages and disadvantages of the federal system are shown in the table below: Advantages Disadvantages It is suitable for managing the diversities of the country. It is an expensive form of the governance .....

14. Are there machines which spin from outside but stays still from inside without any support?

You might have seen a drum full of water. Have you noticed when you roll the drum the water will not move or roll? This is due to a moment of inertia in water. The try to stay in rest. And there is no type of machine till .....

15. नेपालको विकास कृषिबाट होइन, पर्यटन उद्योगबाट हुन्छ ।

पक्षबाटः आदरणीय सभापतिज्यू, प्रमुख अतिथिज्यू, निर्णायक मण्डल, गुरुवर्ग र यहाँ .....

16. Solve the question number 7 of given figure.

a) Ammonia(NH3) b) 2NH4Cl + Ca(OH)2 ⟶ CaCl2 + 2H2O + 2NH3⤒ c) A moist red litmus peper. d) In order to preventing it from .....

17. Answer the following questions after observing the figure :

a)What does the apparatus represent?
b)Name the chemicals used in this apparatus.
c)Write the chemical reaction taking place between two chemicals used in this apparatus.
d) Name the gas produced by the reaction between two chemicals used in this apparatus.
e)Write an application of this apparatus.

a) Apparatus represent the fire extiguusher. b) Sodium bicarbonate(NaHCO3) and Sulphuric acid(H2SO4). c) 2NaHCO3 + H2SO4 ⟶ Na2SO4 + 2H2O + 2CO2. d) CO2 (Carbon dioxide). e) It is used for extinguishing .....

18. Why is Nepal so behind in hydro-power generation?

Following are the reasons behind Nepal's failure to generate hydro-electricity: - Lack of awareness among the people regarding the advantages of running small-scale hydropower in a small area. - Lack of capital resource for making the .....

19. If 3 times the square of a number is equal to 9 times the number,find the number.

Here, Let the required number be x, Then, 3x2 = 9x or, 3x2 - 9x = 0 or, 3x(x - 3) = 0 Either, 3x = 0 ⟹ x = 0 Or, x - 3 = 0.................Find x. Thus, the required number is .....

20. The price of a machine is depreciated by 5% per year. If it's present price is rs 86,640.How many years ago,it's price was rs 96,000

Here, Dipreciassion rate = R = 5%. Present price = PT = Rs.86,640 Price before T years = P = Rs.96,000 Time = T = ? We know, PT = P( 1 - R/100)T or, 86640 = 96000 ( 1 - 5/100)T or, 86640/96000 = (19/20)T or, .....

21. In the given figure, AB = AC, BD = EC & ∡DAE = 40^o. Prove that the ∆ADE is an isoscles and calculate the size of ∡ADB.

Here, To show ∆ADE is an isosceles, we have to show triangles ADB & AEC are congurrent. For this, In ∆ADB & ∆AEC, i) AB = AC(S) [ .....

22. The sum of two number is 35. If one number exceeds by 5. Find the number

Let the greater number be x anf smaller be y. Then, from the first case, x + y = 35........................(i) From the second case, x = y + 5............................(ii) Substituting value of x from (ii) in (i), we get .....

23. Simplify:
(√7 + √5)(√7 - √5)

Here, (√7 + √5)(√7 - √5) = (√7)2 - (√5)2 [ Since, (a + b)(a - b) = a2 - b2.] = 7 - 5 = 2, which is the required .....

24. ‘मेरो घर’ कविताको मूल भाव लेख्नुहोस् ।

‘मेरो घर’ कविता प्रभा भट्टरार्इद्वारा रचिएको प्रतीकात्मक कविता हो । यहाँ .....

25. सुगौली सन्धिपश्चात् वि. सं. १९०३ सम्मको अवधि नेपालको राजनीतिक अस्थिरताको समय थियो । पुष्टि गर्नुहोस्।

(क) भारदारहरू विभिन्न गुटमा लाग्दा उनीहरूबिचको झगडा, (ख) राजाको कमजोर स्वभाव, (ग) रानीहरूको आपसी .....

26. What works are carried out by the Village Executive?

- It provides basic health and sanitation services in the village. - It keeps the records of birth, death, marriage and migration. - It makes necessary arrangements for the protection of watersheds, wildlife, mines and .....

27. Fill in the blanks with the words given in the box below.

a) Human beings are ................ beings.
b) Social institutions have different ........................... .
c) The function of school is to provide .....................
d) A post office ............... letters and parcels.
e) ..................... recommends citizenship in the village.

a) Human beings are social beings. b) Social institutions have different functions. c) The function of school is to provide education. d) A post office exchange letters and parcels. e) VDC recommends citizenship in the .....

28. What do you mean by Deuki system? Define.

Deuki is a bad custom still prevalent in some rural areas of Nepal. It is the system of offering a girl child to the temple with the belief to collect religious merits. Parents generally offer 5 to 6 years old child to the temple. Some wealthy .....

29. What it moon?

Moon is the natural satellite of the earth, which we see in the sky during night .....

30. Solve the puzzle below.

Study the word-puzzle .....

31. What are the main function of national women's commission find out about it and list them

The main function of National Women Rights Commission are as follows: - To formulate policies and programs regarding women welfare for the Government of Nepal and forward them to the Government for implementation. - To review whether or not .....

32. Solve the clues
a.Figure to build out of snow
___ ___ ___ w ___ ___ ___
b. Be aware of
___ ___ o w
c.Knot in shoelaces
m o ___
d.Needing to repay money
o w ___ ___ g
d.A "weeping" tree
__ __ __ __ __

Could you please post the .....

33. Every man has to lend to humanity as much as s/he can. Serving the people is helping the society and nation to grow up. Justify the statement with an example.

Definitely, serving the people is helping the society. You know serving the people means contributing to the transformation of society. For example, helping the poor people means helping the .....

34. Discuss the major achievements made by Kailash Satyarthi. Also, mention what role we should play for the protection of child rights in Nepal.

Kailash Satyarthi is known for his 'save childhood' movement. He initiated this movement to fight against the child labour. He has waged a peaceful struggle to stop children from being exploited as labour instead of attending school. He .....

35. What should we learn from the story of Satyarthi and Dr. king? Mention in four points.

Martin Luther King was a black political activist. He advocated for the civil rights of the blacks in the USA. The black people were treated very badly during his times. So, he decided to fight against the injustice to put an end to it. So, he .....

36. Why do all organisms have an even no. of chrosome?

The reason why the majority of organisms have an even number of chromosomes is because chromosomes are in pairs. Another exception would be polyploidy , which occurs when organisms have more pairs .....

37. What is the difference between wood and stone?

Wood Stone 1. It is organic. 1. It is inorganic. 2. It floats on water. 2. It sinks in water. 3. It burns. 4. It decays. 3. It does not burn. 4. It does not .....

38. How is it possible to put air in the tyre of a bicycle?

Here, First, remove the plastic cap that might be covering the end of your tyre of a bicycle valve. Unscrew the tiny locking nut situated in the valve. You should be able to hear and feel a bit of air comes out from the .....

39. If f(x)=x+2 ang g(x+1)=x+1then find gof(4).

Here, f(x)= x + 2 g (x+1) = x + 1 Replace x + 1 with x we get, g(x) = x Now, gof(4) = g {f(4)} = g (4 + .....

40. Write the functions of National Women Commission.

It carries out following functions: - To formulate policies and programs regarding women welfare for the Government of Nepal and forward them to the Government for implementation. - To review whether or not statutes related to women’s .....

41.

FILL IN THE BLANKS WITH CORRECT WORDS.

Mr. Khadka was just shutting his shoe shop at the end of the day. …………………… a man in the suit walked in …………………… asked for an expensive pair of shoes. There was something about the way the man walked ……………….. made Mr. Khadka suspicious.

Mr. Khadka felt …………………….he had seen him before somewhere and then remembered he had …….. on TV! The man was wanted criminal! The man tried on a few pairs of shoes……………………. He brought a pair which Mr. Khadka strongly recommended.

“They are a bit tight,” the man complained. “They will stretch, sir,” Mr. Khadka said.

…………………………. Mr. Khadka had expected, the man limped into the shop the next day. ………………………. Complained about the shoes. ……………………………. He entered the shop, he was surrounded by police. Mr. Khadka had deliberately sold the man a pair of shoes …………………….were a size a too small,………………… he would returm them the next day.

and, as, in order to, as soon as, before, when, knowing that, that, which

1. as 2. and 3. which \ 4. knowing that 5. that 6. as soon as 7. in order to 8. before 9. which 10. .....

42. tan²300⁰ . sec²120⁰ - sin210⁰ . cos60⁰ = 49/4

Here, LHS = tan23000 . sec21200 - sin2100 . cos600 = tan2(360 - 60)0 . sec2(180 - 60)0 - sin(180 + 30)0 . cos600 .....

43. Leaves in lotus are broad flat that float on the water. Write reason on the basis of adaptation.

The upward force generated by the fluid (generally water) opposes the downward force exerted by the weight of the lotus.

The leaves also happen to be very broad in comparison to their weight meaning very little pressure is exerted on any .....

44. On the basis of habitat, write any two adaptational characteristics of algae.

Algae are eukaryotic organisms that have no roots, stems, or leaves but do have chlorophyll and other pigments for carrying out photosynthesis. Algae can be multicellular or unicellular. Unicellular algae occur most frequently in .....

45. F(x)=x²-2x+8 and g(x)=x²-5x+6 then find fog and gof

Here, F(x)=x2 -2x+8 g(x)=x2-5x+6 Now, fog(x) = f(x2 - 5x + 6) = (x2 - 5x + 6 )2 - 2(x2 - 5x + 6) + 8 = (x2-5x)2 + 2.((x2-5x).6 .....

46. If A, B and C are angles of a triangle, then prove that:
tan(A + C)/2 = cotB/2

Here, A, B & C are the angles of a triangle. So, A + B + C = 180o [ Since, the sum of angles of a triangle is 180o.] or, A + B = 180o - C or, A/2 + B/2= 90o - C/2 .....

47. If 4α = 6β = 360o, then show that: sin²α + cos²β - cot²β = 11/12

Here, 4α = 360o ⟹ α = 900 6β = 3600 ⟹ β = 600 Now, LHS = sin2α + cos2 β - cot2 β = (sin 900)2 + .....

48. If A,B and C are angles of triangle, then prove that:
tan(A+C) = - tanB

Here, A, B & C are the angles of a triangle. So, A + B + C = 180o [ Since, the sum of angles of a triangle is 180o.] or, A + C = 180o - B Operating both sides by tan, we .....

49. If A,B and C are angles of a triangle, then prove that :
cos(B+C) = - cosA

Here, A, B & C are the angles of a triangle. So, A + B + C = 180o [ Since,the sum of angles of a triangle is 180o.] or, A + B = 180o - C Operating both sides by cos, we .....

50. If A,B and C are angles of a triangle, then prove that :
sin(A+B)= sin C

Here, A, B & C are the angles of a triangle. So, A + B + C = 180o [ Since, the sum of angles of a triangle is 180o.] or, A + B = 180o - C Operating both sides by sin, we get .....