Model Question Nepali XII

 

Model Question Social XII

Model Question English XII

3. Compulsory English (ENG. 004)

Compulsory English (ENG. 004)

Grade XII Model Questions

Full Marks: 75 Time: 3 hours

1. Read the text and complete the tasks that follow. 15

   How to stay fit, happy and healthy

   If you’ve been listening to the news you already know about our national obesity levels rising by the day. It has never been more important to watch what you are eating and to get an adequate amount of exercise and sleep to keep yourself fit and healthy. Though it may feel like really hard work at first, once you adopt an exercise routine and start to adapt to a new situation, you’ll forget you ever did things differently. Here are the top four top adjustments you could make make:

   
   

   Sleep is huge and almost a third of the US population doesn’t get near enough to help them stay physically and mentally healthy. If you are sleep deprived, try changing your habits in order to get a full eight hours every night.

   
   

   Look at what you’re eating now and make changes where you see fit. If you are susceptible to snacking, keep a piece of fruit or a few nuts at hand. The key is to eat small meals throughout the day. Reduce portion sizes, remove white bread and replace with whole grains and make sure each meal contains at least one portion of fruit and – or vegetables. Healthy food doesn’t have to be expensive in the least bit, and you can get an abundance of low priced fruit and veggies, like apples, bananas, potatoes and peas.

   
   

   Take a look at your current lifestyle and make a small list of everything you do that is not good for your health. This could be anything, from eating too much junk food or drinking too much caffeine, to smoking or drinking. Start the process of breaking these habits one by one. Some will be easy, while others may take months or maybe years to get rid of and eradicate completely from your life, but the sooner you start fighting, the better.

   
   

   Some addictions (like smoking, drugs or alcohol) are incredibly bad not only to your health, but also to your pocketbook. If you smoke and/or drink, start by cutting back on how many drinks you have, or cigarettes you smoke, in a day, and if necessary, seek medical advice and assistance to make further steps towards stopping completely.

   
   

   We all should be doing at least 30 minutes of exercise, 3 to 4 or more times a week, to maintain good health and keep fit. This can be pretty much anything that is physical, like walking, cycling, running, swimming to weightlifting, etc. This too does not have to be expensive, and you can get a great work out without joining any costly gyms. Most of these exercises are inexpensive, and just doing a cardiovascular exercise, like walking, jogging, or walking on a treadmill a few times a week will do your body (and heart) good.

   1. Look at the highlighted words in the text. Complete these sentences using them. Two of them are not necessary. (5X1=5)

      1. Disadvantaged people are of social justice.

      2. Nepal is a naturally rich country. In fact, it has an of natural resources.

      3. Older people with medical complications are to Covid-19.

      4. I have made a few to the design to give the shirt a new look.

      5. It took me seven hours to complete the task. It was difficult.

   2. Choose the appropriate headings for paragraphs 2-6 from the list below and write the paragraph numbers next to them. (5X1=5)

      1. Strive for a better diet …………….

      2. Exercise, exercise, exercise …………….

      3. Overcoming addictions …………….

      4. Get more sleep …………….

      5. Stop all those bad habits …………….

   3. Answer the following questions. (5X1=5)

      1. What percentage of the US population get enough sleep to stay healthy?

      2. Why is healthy food not always expensive?

      3. What is the best way to get rid of bad habits?

      4. Why do you think an addiction like smoking is worse than snacking on junk food?

      5. What type of exercise is good for your heart?

2. Write short answers to the following questions. (5X2=10)

   1. Why were the people in the neighbourhood surprised at the role of the young man and his wife within their family? (Neighbours)

   2. How does the author make fun using the words 'America' and 'the USA? (A Devoted Son)

   3. Explain the following lines with reference to the context: (The Awakening Age) Along the line may our lives rhyme

      To make a loving harvest of space and time.

   4. What is the central idea of the essay Knowledge and Wisdom by Bertrand Russell?

   5. How can you say that history has been a major contested issue in this present world? (Humility)

3. Write long answers to the following questions. (2X5=10)

   1. Sketch the character of Famous Actress. How is she different from Earnest Young Woman? (A Matter of Husbands)

   2. Write a short summary of the poem A Day by Emily Dickinson.

4. What is the most useful thing that you have ever learnt? Write two or three of paragraphs about it. 7

5. You have received this email from your friend Nitesh.

   From: Nitesh

   Subject: Holiday

   Some school friends of mine are visiting your village soon for a week's touring holiday. They would like to travel around about your local area and understand its history.

   Can you tell me about some of the places they could visit please? What's the best way to travel around – bus, car, bike or on foot?

   Thanks, Nitesh

   
   

   Write a reply email to Nitesh. 8

6. Many students in Nepal tend to choose to study abroad. To what extent does this trend benefit the students and the country? What are the drawbacks? Write an essay to explain your thoughts in about 300 words. 10

7. Do as indicated in the brackets and rewrite the sentences. (10X1=10)

   1. I’m going to tell you something very important, so please listen …………... .

      (Complete the sentence with an appropriate adverb.)

   2. The old man died a heart attack. (Put the correct preposition in the blank.)

   3. More than one person going to have to find a new job. (Put the correct

      verb in the blank.)

   4. You'll (has to/have to/must/had to) tell the police that your house was

      broken into. (Choose the correct option from the bracket to complete the sentence.)

   5. He only realised he his keys when he reached his front door. (Complete the

      sentence using correct forms of verbs: lose)

   6. A lot of people are worried about (to lose/losing) their jobs. (Choose the

   correct option from the bracket to complete the sentence.)

   g the AC was on, the room was not cool. (Put a correct conjunction in the

   blank to complete the sentence.)

   1. Between 2000 and 2005 she wrote three novels, (neither of which/none

      which/none of which) were published. (Choose the correct option from the bracket to complete the sentence.)

   2. I like people laughing at me. (Change into passive.)

   3. Could you please open the window? (Report this with the reporting clause: She

   requested )

8. Choose and copy the correct answer. (5X1=5)

1. Which of the following words has a different initial sound?

   1. check ii. chess

      iii. chemical iv. chairman

2. The last sound in the word 'push' is transcribed as

   1. /ʃ/ ii. /z/

      iii. /s/ iv. /tʃ/

3. I can't the pain.

   1. bare ii. bear

      iii. beer iv. bore

4. Which word would you find in a dictionary that comes between the guide words: kiwi …

   knit?

   1. king ii. kitty

      iii. knob iv. knife

5. The babysitter the girl while her parents were not at home.

   1. looked after ii. looked at

iii. looked over iv. looked up

–)–

Model Question Computer XII

 

Model Question Biology XII

Model Question Chemistry II

Physics Model Question XII

Dispersion

Here is a complete note on Disperison of light.

Magnetic Material

aBasic concept of Magnetism A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on otherferromagnetic materials, such as iron, and attracts or repels other magnets. Magnetic field: A magnetic field is the magnetic effect of electric currents and magnetic materials. The magnetic field at any given point is specified by both a directionand a magnitude (or strength); as such it is a vector field. Magnetic lines of force:The imaginary path in the magnetic field through which unit north pole moves is allowed to do so is called magnetic lines of force. Magnetic lines of force are the lines in the magnetic field , tangent at a point of which shows the direction of Magnetic field at that point.Properties of Magnetic lines of force:1. Magnetic field lines are continuous closed imaginary lines.2. They never intersect each other.3. A tangent drawn at a point in magnetic lines of force show the direction of magnetic field at that point.4. Magnetic lines of force are more crowded where filed is strong and is less crowded at weaker field.5. They are directed from north pole to south pole externally and from south pole to north pole internally in a magnet.Magnetic FluxMagnetic flux ɸ through any surface area in a magnetic field is defined as the number of magnetic lines of force crossing through the surface. Magnetic field intensity:-The strength of a magnetic field at a point is called the magnetic field intensity.The magnetic field intensity at a point defines as the force experienced by a unit North Pole at that point. It is measured in Telsa(T) or Gauss. Intensity of magnetization: It is defined as the net magnetic moment per unit volume of a magnet along the direction of applied magnetic field. It is denoted by I. It is a vector quantity.I= Magnetic moment (M)

Volume (V)=M

VThe unit of I is ampere per meter (Am-1).Magnetic intensity (H): The degree to which a magnetic field can magnetize a material is called magnetic intensity. It is denoted by H. It is a vector quantity. Its unit is ampere per meter (Am-1). It is also called magnetic force. Magnetic intensity magnetize the magnetic substance when placed in this field.H=B

𝜇

What is the difference between Magnetic Intensity and Intensity of Magnetisation? Answer: The magnetic intensity defines the forces that the poles of a magnet experiences in a magnetic field whereas the intensity of magnetization explains the change in the magnetic moment of a magnet per unit volume.

Total magnetic field (B) :

When a magnetic substance is placed in an external magnetic field, it gets magnetized. The resultant magnetic field within the magnetic material is the vector sum of magnetic field due to applied field and the induced magnetic field due to the material itself.Its SI unit is weber m2 or Tesla (T). Its CGS unit is gauss (G)Therefore, total magnetic field B, is written as, B= Applied field (B0)+ magnetic field due to the magnetization of material (BH) i.e. B=B0+BHThe terms B 0 and BH can be expressed into H and I respectively.The strength of applied field due to the magnetic intensity H, B0=𝜇0H and BH=𝜇0I=𝜇0𝜒HWhere, 𝜒 is dimensionless quantity and is known as magnetic susceptibility. The magnetic susceptibility indicates the degree of magnetization of a material in response to an applied magnetic field.Therefore, a

B	=𝜇0H+𝜇0𝛾H
	=𝜇0(1+𝛾)H

Also, in the material medium, total magnetic field B is directly proportional to the magnetic intensity H.i.e. B∝HB=𝜇HWhere, 𝜇 is the absolute permeability of a medium. So, we write, 𝜇=𝜇0(1+𝜒)Magnetic SusceptibilityMagnetic susceptibility of a magnetic substance is the ratio of intensity of magnetization to the magnetic intensity. It is denoted by 𝜒. It has no unit. It is the property of substance.a

∴ 𝜒	= intensity of magnetization (I) magnetic intensity (H)
𝜒	=I H

Magnetic susceptibility 𝜒 measures how much extent the materials can be magnetized. The magnetic materials which can be magnetized strongly, have the value of 𝜒 high positive value. This type of materials are called ferromagnetic materials. The magnetic materials which are weakly magnetized have the value of 𝜒 small positive value. This type of materials are called paramagnetic materials. Likewise, the magnetic materials which are weakly magnetized in the opposite of applied field are called diamagnetic materials. The value of 𝜒 is small negative for these type of materials.Relative PermeabilityAbsolute permeability of a material medium is a measure of the amount of resistance encountered when forming a magnetic field in that medium. It is denoted by 𝜇. If the absolute permeability is taken for the free space (or vacuum), it is denoted by 𝜇0. It is also called the permeability constant. The ratio of absolute permeability of a medium to permeability constant is called relative permeability. It is denoted by 𝜇r. Therefore,Relative permeability (𝜇 r)=𝜇

𝜇0It is a dimensionless quantity. The relation between absolute permeability and magnetic susceptibility is,a

𝜇=𝜇0(1+𝜒)

𝜇 𝜇0=1+𝜒

𝜇r=1+𝜒

Classification of Magnetic MaterialThere are three types of magnetic materials. They are:1. Diamagnetic material2. Paramagnetic material3. Ferromagnetic materialDiamagnetic materialThose substances which are feebly magnetized in the direction opposite to the applied field are called diamagnetic material. Examples of diamagnetic materials are bismuth, copper, water, mercury, alcohol, argon, gold,tin, mercury, antimony etc. The magnetic moment of atoms of a diamagnetic material is zero. They acquire induced dipole moments when the material placed in an external magnetic field. These moments are in opposite in the direction to the applied field.Some properties1. The diamagnetic materials are repelled by magnets.2. When a diamagnetic liquid in a watch glass is placed over two closely spaced pole pieces of the magnet, it is depressed at the middle while in the case of pole pieces separated by a distance, it rises at the middle. Similarly, when a diamagnetic liquid is placed in a U-tube and one of the limbs of the tube is placed between the two strong pole pieces of magnet, the liquid depressed at that limb.3. The diamagnetic materials move from a stronger to a weaker field.4. A diamagnetic rod, freely suspended in a magnetic field, slowly turns to set at right angle to the applied field.5. Since magnetized is opposite in direction to an applied field, the diamagnetic materials have the small value for the intensity of magnetization, I.6. The materials have always negative magnetic susceptibility, and accounts from -10-6 to -10-5.7. These materials are independent of temperature.Paramagnetic MaterialThose materials which are weekly magnetized in the same direction of the applied magnetic field are called paramagnetic material. The examples of paramagnetic materials are aluminum, chromium, oxygen, manganese, alkali, alkaline earth metal etc.The paramagnetic materials have permanent magnetic moments. These moments interacts weekly with each other and randomly orient in the different direction.Some Properties1. The paramagnetic materials are feebly attracted by magnets.2. A paramagnetic rod, freely suspended in a magnetic field, aligns along the field.3. The paramagnetic materials are temperature dependent and follow curve law.4. The relative permeability is nearly unity than ranges from 1.00001 to 1.003 for common ferromagnetic materials at room temperature. So, the magnetic lines of force inside the material placed in a magnetic field are more than that outside it.5. The susceptibility of paramagnetic substances has small positive value.Ferromagnetic MaterialThe ferromagnetic materials are highly magnetized in a magnetic field. The examples of ferromagnetic materials are iron, nickel and cobalt, and their alloys such as alnico. Gadolinium and dysprosium are ferromagnetic at low temperature.Some Properties1. Ferromagnetic materials are highly attracted by magnets.2. Ferromagnetic materials more from weaker to stronger field.3. A ferromagnetic rod, freely suspended in a magnetic field, turns fast to set along the applied field.4. The magnetic susceptibility is positive and very high and varies with applied field.5. The relative permeability is very high in the order of 1000 to 100,000.6. Ferromagnetic dust in a watch glass, placed over two closely spaced pole-pieces of the magnet, increases at the middle, while pole piece is separated by a distance, depresses in the middle.Domain Theory of Ferro Magnetism

Magnetic domain in ferromagnetic material:

Each atom of ferromagnetic substance has a permanent magnetic substance; in the unmagnetised state, the atomic and molecular dipoles are arranged in random so the net magnetic moment is zero. There is a strong interaction with neighboring atoms which keeps their magnetic moment aligned parallel in small regions even in the absence of an external field. These small regions with the volume ranging between 10-12 to 10-8 m3 are called domains. When the material is placed in an external field BO, the domains tend to orient themselves parallel to field B0. As the applied field becomes stronger, the domains, having magnetic moments not aligned with the field, become very small and when the domains fully align to the applied field, the material attains magnetic saturation. On removing the field, the domain walls do not move completely into previous positions. This means material retains a magnetization in the direction of the applied field.HysteresisLagging of magnetic field B behind the magnetic field H in a ferromagnetic material taken through a cycle of magnetization is called the hysteresis.

Hysteresis loop in Ferromagnetic Material:

A ferromagnetic material (iron) is taken and is placed on an external field B0. Now the magnetic field B in the material is studied with the magnetic intensity H ( = B0

𝜇0) is compared. When H is increased the value of magnetic field B increases and reaches maximum value Bs at point A. The value of magnetic field doesnot increases on increase in H. Now lowering the value of H, decreases the magnetic field but doesnot become zero when H is made zero. Value of magnetic field remains BR. (Through AR). H is reversed, then magnetic field continues to decrease and becomes zero at point C. Further increasing the value of H, magnetic field changes its direction and reaches maximum in oppoiste direction at point D. Now again H is decreased and made zero at point E, again reversed the reaches 'F' and ultimately 'A'. The closed loop denotes: a) loss of energy during magnetization b) how strongly is the material magnetizedArea of the hysteresis loop is directly proportional to the elergy loss.The material with broad hysteresis loop with higher retentivity (OR) and coercivity (OC) is suitable for making permanent magnet. Greater area of loop means greater energy has been lost during magnetization thus greater work should be done to demagnetize it. (As in steel)- Suitable for making permanent magnet Less area of loop with low value of coercivity means magnetization can be destroyed easily. ( as in soft iron) - Suitable for making core of transformer.Material with greater value of HC are called magnetically "Hard".

(a) Hysteresis loop in steel (b) Hysteresis loop in soft iron: