CBSE Question Papers

1. Write a balanced chemical equation for the reaction between sodium carbonate and hydrochloric acid indicating the physical state of the reactants and the products. (1 Marks)


2. Write the structural formula of chloromethane.(1 Marks)


3. What is the valence of silicon with atomic number 14? (1 Marks)


4. How should a ray of light be incident on a rectangular glass slab so that it comes out from the opposite side of the slab without being displaced? (1 Marks)


5. An object is kept at a distance of 4 m in front of a spherical mirror which forms its magnification? Is the mirror concave or convex?(1 Marks)


6. A girl was playing with a thin beam of light from her laser torch by directing it from different directions on a convex lens held vertically. She was surprised to see that in a particular direction the beam of light continues to move along the same direction after passing through the lens. State the reason for this observation.(1 Marks)


7. Elements magnesium and oxygen respectively belong to Group 2 and Group 16 of the Modern periodic Table. If the atomic numbers of magnesium and oxygen are 12 and 8 respectively, draw their electronic configurations and show the process of formation of their compound by transfer of electrons. (2 Marks)


8. What happens when chlorine is passed over slaked lime at 313 K? Write chemical equation of the reaction involved and state two uses of the product obtained. (2 Marks)


9. Name four gases commonly present in biogas. State two advantages of using this gas over fossil fuels. (2 Marks)


10. The electrical resistively of silver is 1.60× 10^-6Ωm. What will be the resistance of a silver wire of length 10 m and cross –sectional area 2 × 10^-6 m²? (2 Marks)


11. What is meant by spectrum of white light? How can we recombine the components of white light after a prism has separated them? (2 Marks)


12. How are the wastes produced in nuclear power plants different from those produced in a thermal power plant? What happens to the waste of a nuclear power plant? (2 Marks)


13. With the help of balanced chemical equations explain what happens when ethanol is heated with
    (i) alkaline solution of potassium permanganate,
    (ii) excess concentrated sulphuric acid at 443 K. Mention any two uses of ethanol. (3 Marks)


14. In the following table six elements A, B, C, D, E and F (here letters are not the usual symbols of the elements ) of the Modern Periodic table with atomic numbers 3 to 18 are given : (3 Marks)

(a) Which of these is (i) a noble gas, (ii) a halogen?
(b) If B combines with F, what would be the formula of the compound formed?
(c) Write the electronic configurations of C and E.

15. The image of an object placed at 60 cm in front of a lens Is obtained on a screen at a distance of 120 cm from it. Find the focal length of the lens. What would be the height of the image of the object is 5 cm high? (3 Marks)


16. How can a magnetic field be produced without using a magnet? Describe an experiment to show that a magnetic field exerts a force on a current carrying conductor. (3 Marks)


17. Derive an expression for the heat produced in a conductor of resistance R when a current I flows through it for time t. Two identical resistors of resistance R are connected in series with a battery of potential difference V for time t. The resistors are then connected in parallel with the same battery for the same time t. Compare the heat produced in the two cases. (5 Marks)
    Or
    Deduce the expression for the equivalent resistance of the parallel combination of three resistors R₁, R₂ and R₃. Consider the following electric circuit:
    

    

    
    (i) Which two resistors are connected in series?
    (ii) Which two resistors are connected in parallel?
    (iii) If every resistor of the circuit is of 2 Ω what current will flow in the circuit? (5 Marks)


18. Give reason why
    

    (i) Metals are good conductors, whereas non – metals are
    had conductors of electricity.
    (ii) Metals replace hydrogen from acids whereas non –metals do not .
    (iii) An iron knife dipped in a blue copper sulphate solution turns the blue solution light green.
    (iv) Sodium is kept under kerosene.
    (v) Carbon cannot reduce the oxides of sodium or aluminum. (5 Marks)

    
    Or
    (a) Write two differences between calcinations and roasting.
    (b) No reaction takes place when granules of a solid ‘A’ are mixed with a powder of solid ‘B’ However when the mixture is heated a reaction starts with evolution of much heat. Product ‘C’ of the reaction settles down as a liquid metal and solid product ‘D’ keeps floating over the liquid ‘C’ This reaction is sometimes used for making metal for ready use in odd places .
    

    (i) Based on this information make assumptions about ‘A’ and ‘B’ And corresponding dedications about ‘C’ and ‘D’ and write a balanced chemical equation for the reaction. Include in the equation the information about physical states of the reactants and reaction being exothermic.
    (ii) Name two types of chemical reactions to which this reaction Can belong. (5 Marks)

19. State the basic difference between the processes of respiration and photosynthesis.


20. Name the intermediate and the end products of glucose break down in aerobic reparation.


21. Name any two types of tropism


22. Why is variation beneficial for the species, but not necessarily ro the individual?


23. State any four personal choices you would like to make to reduce energy consumption without affecting the quality of life or work explaining how each one of them would help you to do so .


24. Describe how decomposers facilitate recycling of matter in order to maintain balance in the ecosystem. (2 Marks)


25. With the help of suitable examples explain natural selection. (3 Marks)


26. Design an experiment to demonstrate that the roots bend in the direction of water stimulus. (3 Marks)


27. Draw a neat and labeled diagram of human respiratory system. Explain in brief the role of lungs in the exchange of gases. (5 Marks)
    Or
    Draw a neat and labelled diagram of human excretory system. Describe in brief the function of kidneys, urethras, Urinary bladder and urethra. (5 Marks)

1. (a) Why is a business establishment divided into different
   Departments? Explain. (5 Marks)
   (b) what is ‘vertical filing ‘ ? Explain. (5 Marks)
   (c) What are the main objectives of an office ? Explain. (5 Marks)
   (d) List the main advantages of card Index. (5 Marks)

2. (a) what is a business letter ? Explain any five qualities of a good business letter.(10 Marks)
   (b) Write a Complaint letter to Birla Whit Cement of Rajasthan regarding the short supply of quantity in 1000 cement bags purchased last week. (10 Marks)

3. (a) Enmerate the long term sources of finace of business of organizations. (10 Marks)
   (b) What is meant by borrowed funds ? Explain any three (5 Marks)
   (c) What are the main functions of a stock exchange ? Explain. (5 Marks)
   (d) Give any five merits of ownership funds. (5 Marks)

4. (a) Explain briefly any two of the following : (5 Marks)

   (i) A.T.M (ii) Debit Card (iii) Credit Card 

5. (a) Explain briefly thediffent methods of granting loans by a Banks. (5 Marks)
   (b) You want to open a current account in State Bank of India of your locality. Explain briefly the procedure; you will follow to open the account. (5 Marks)
   (c) what is Bank Draft ? Why is it drawn? By whom and on whom is drawn ? (5 Marks)


6. (a) What is meant by Negotiable Instruments ? What are their characteristics ? Explain. (5 Marks)
   (b) What is meat by Bills of Exchange? Give any three differences between Bills of Exchange and promissory Notes. (2+3=5 Marks)
   (c ) Give any five reasons for dishonoring of cheque. (5 Marks)
   (d ) Differentiate between crossing and endorsement of a cheque. (5 Marks)

1. prepare Final Accounts of Ayodhya Traders for the year ending 31^st March 2009 from the following balances and the given adjustments :

Particulars	Rs .	Particulars	Rs.
Salaries Repairs Cash Interest Received Drawings Debtors Bills Payable Opening Stock Bank Overdraft Carriage Inwards	36,000 2,500 1,000 3,000 24,000 38,000 4,000 30,000 3,10,000 .2,000	Creditors Traveling Expenses Return Outwards Machinery Building Sales Return inwards Capital Purchases	4,500 5,000 4,000 2,10,000 4,50,000 3,80,000 5,000 2,43,000 1,45,000

Adjustments:

(i) change depreciation on machinery at 10 % p.a.
(ii) Traveling expenses include Rs 1,200 for 2009-10.
(iii) Repairs due Rs. 300.
(iv) Debtors were bad to the extent of Rs 6,000.
(v) Create a provision for doubtful debts @ 5%.
(vi) Stock on 31st march 2009 stood at s. 14,200. (20 Marks)

2. (a) What is bank Reconciliation Statement ? How is it prepared? 8 Explain giving suitable examples(8 Marks) .
   (b) From the following particulars ascertain the bank balance as per passbook of Mr. Tarachand as at 31st March, 2009.

(i) credit balance as per case book on 31st March 2009 was Rs. 30,000.
(ii) Interest charged by bank upto 31st March 2009 Rs. 1000 is recorded in a passbook only.
(iii) Bank charges Rs. 250 were not recorded in the case book.
(iv) cheques paid into bank Rs. 12,500 on 29.3.2009 have not yet been credited by the bank .
(v) Cheque issued for Rs. 30,000 have not yet been presented for payment.
(vi) Divided collected directly by bank Rs 9,000 has not been entered in cash book. (12 Marks)

3. (a) Differentiate between Bills of Exchange and Promissory Notes on the basis of
   

   (i) parties
   (ii) Nature
   (iii) Acceptance
   (iv) Liability and
   (v) Number of copies. (10 Marks)

   
   (b) on 1*January 2010, Abhay sold goods to Binay of the value of Rs. 1,00,000 and drew upon him a bill at two months for the amount. Binay accepted the draft. On due date, he expressed his inability to meet the bill and offered to pay the full about within three days with interest rs 1000. The proposal was accepted and abount was paid in time. Pass jounal entries in the books of abhay and Binay. (10 Marks)

4. (a) Explain the meaning of errors of omission and errors of compensating .Give three examples of each. (8 Marks)
   (b) Rectify the following errors found in the books of chakaleshwar & sons :

(i) purchases of rs. 5,000 from Devdass on credit were recorded in purchases book as rs 50 only.
(ii) An amount of rs 25,000 paid to Shrinath was wrongly debited to Hairnet ‘s A/C.
(iii) Furniture was written off by Rs. 1,000has not been posted toatio. depreciation A/C.
(iv) Goods sold for Rs. 2,380 were posted to sales A/C as Rs.2,830.
(v) Is war Dass a customer has deposited Rs. 2,500 in the bank directly in the name of chakaleshwar but no entry so far has passed anywhere in his books.
(vi)Accountant deposited fee Rs. 40,000 of his son being a student of Engineering. But entry was made as miscellaneous expenses paid. (10 Marks)

5. (a) Explain the need for providing deprecation on fixed assets with examples.(8 Marks)
   (b) On 1.7.2007, Mangol Ltd. Purchased a machine for Rs. 2,50,000 A part of machinery which was purchased for Rs. 20,000 on 1st July 2007, become obsolete and was disposed off for Rs. 2,000 on 1st October, 2009 Depreciation is charged @ 10% annually on written down value. Show machinery A/C for the years 2007 ,2008 and 2009. The books are closed on 31st December every year. (12 Marks)

1. Explain briefly the functions of any five of the following parts of a type writer: (5 Marks)

(i) Variable line spacer
(ii) Shift lock
(iii) Space bar
(iv) Shift key
(v) Platen
(vi) Bichrome switch
(vii) Letter keys

2. Give standard abbreviation for the following .(any five):
   

   (i) Demi –official
   (ii) Centimeter
   (iii) Singned
   (iv) Cost insurance and freight
   (v) Please trun over
   (vi) Office order
   (vii) Value payable post

   
   OR
   How many spaces will you leave before and after while typing the following punctuation marks ? (any five):

(i) colon
(ii) Hyphen
(iii) Full stop
(iv) Comma
(v) Semicolon
(vi) Sign of plus (+)
(vii) Sign of exclamation (5 Marks)

3. Give proof correction signs for the following :(5 Marks)

(i) centralize the heading
(ii) equalize spacing
(iii) Begin new paragraph immediately after bracket sign
(iv) Insert hyphen
(v) Omit

5. (a) What precautions should be taken while cutting stencil on a type – writer ? (3 Marks)
   (c) What for are the following used : (2 Marks)
   

   (i) correcting fluid
   (ii) stylus pen

6. Explain in brief any two of the following : (5 Marks)
   

   (i) Difference between shift key and shift lock.
   (iii) Typing a tabulator statement.
   (iv) Fixing margins on a type paper

Question Numbers 1 to 10 carry 1 mark each.

1. Has the rational number  a terminating or a non-terminating Decimal representation?


2. If α, β are the zeroes of a polynomial, such that α+β=6and αβ =4, then Write the polynomial.


3. If the sum of first P terms of an A.P is αp²+bp, find its common difference.


4. In fig. I , S and T are points on the sides P Q and PR, respectively of ΔPQR, such that PT = 2 cm, TR =4 cm and ST is parallel to QR, find the ratio of the areas of Δ PST and Δ PQR.


5. In fig. 2, Δ AHK is similar to Δ ABC. If AK =10 cm , BC = 3.5 cm and H K=7 cm, find AC.
   


6. If 3x =cosec Ø and  find the value of 3 .


7. if P(2, p) is the mind –point of the line segment joining the points A (6,-5) And B (-2, 11), find the value of p.


8. If A(1,2), B(4,3) and C(6,6) are the three vertices of a parallelogram ABCD, Find the coordinates of the fourth vertex D.


9. The slant height of a frustum of a cone is 4 cm and the perimeters (circumferences) Of its circular ends are 18 cm and 6 cm. find the curved surface area of the frustum .


10. A card is drawn at random from a well shuffled pack of 52 playing cards. Find the probability of getting a red face card.

Question Numbers 11to 15 carry 2 marks each.

11. if two zeroes of the polynomial x³-4x²-3x+12 are and - , then find its third Zero.


12. Find the value of k for which the following pair of linear equations have Infinitely many solutions: 2x+3y =7; (k-1)x +(k+2)y = 3k.


13. In an A.P ., the first term is 2, the last term is 29 and sum of the terms i Is 155. Find the common difference of the A.P.


14. if all the sides of a parallelogram touch a circle, show that the parallelogram is a rhombus.


15. Without using trigonometric tables, find the value of the following expression :

Or
Find the value of cosec 30 º, geometrically.

Question Numbers 16 to 25 carry 3 marks each.

16. Prove that  is an irrational number.


17. The sum of numerator and denominator of a fraction is 3 less than twice the denominator. If each of the numerator and denominator is decreased by 1, the fraction becomes ½ find the fraction.
    Or
    Solve the following pair of, equations

18. In an A. P. , the sum of first ten terms is -150 and the sum of its next ten terms is -550 . find the A.P.


19. In fig. 3, ABC is a right triangle, right angled at C and D is the mid – point of BC. Prove the AB² = 4 AD² - 3AC².

20. prove the following :

 Or
Prove the following : (cosec A –sin A) (sec A-cosA )= 

21. Construct a triangle ABC in which BC =8 cm, <B =45º and <C =30º construct another triangle similar to Δ ABC such that its sides are ¾ of the corresponding sides of Δ ABC.


22. Point p divides the line segment joining the points A(2,1) and B(5,-8) such that AP/AB =1/3 , if P lies on the line 2x-y + k = 0, find the value of k.


23. If R(x,y) is a point on the line segment joining the point P(α,b) and Q (b,α), then prove that x + y = α +b.


24. in fig. 4, the boundary of shaded region consists of four semicircular arcs, two smallest being equal. If diameter of the largest is 14 cm and that of the smallest is 3.5 cm, calculate the area of the shaded region.

find the area of the shaded region in Fig. 5, if AC = 24 cm, BC = 10 cm and O is the center of the circle. [Use π =3.14]

25. Cards bearing numbers 1,2,3 , -----,35 are kept in a bag. A card is drawn at random from the bag. Find the probability of getting a card bearing
    a. a prime number less than 15.
    b. A number divisible by 3 and 5.

Question Numbers 26 to 30 carry 6 marks each.

26. Three consecutive positive integers such that the sum of the square of the first and the product the product of the other two is 46, find the integers.
    Or
    The difference of squares of two numbers is 88. if the larger number is 5 less than twice the smaller number, then find the two numbers.


27. prove that ratio of the areas of two similar triangles is equal to the square of the ratio of their corresponding sides. Using the above, prove the following: If the areas of two similar triangles are equal, then prove that the triangles are congruent.


28. From the top of a 7m high building, the angle of elevation of the top of a tower is 60º and the angle of depression of the foot of the tower is 30º. Find the height of the tower.


29. A mild container is made of metal sheet in the shape of shape of frustum of a cone whose volume is 10459 3/7 cm³. The radii of its lower and upper circular ends are 8 cm and 20 cm respectively. Find the cost of metal sheet used in making the container at the rate of Rs. 1.40 per square centimeter.
    
    Or
    A toy is in the form of a hemisphere surmounted by a right circular cone of the same base radius as that of the hemisphere. If the radius of
    Base of the cone is 21 cm and its volume is 2/3 of the volume of the hemisphere, calculate the height of the cone and the surface area of the toy.
30. Find the mean, mode and median of the following frequency distribution :

CBSE class 12th Sample Question Papers

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