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  #2  
31st July 2014, 01:02 PM
Super Moderator
 
Join Date: Apr 2013
Re: CBSE 12 class exam paper of previous year

As you are looking here CBSE 12 class exam paper of previous year for maths /English / Physics, so here I am providing same:

Maths
SECTION - A

1. Which one of the following graphs represent the function of x ? Why ?
y y
x x
(a) (b)

2. What is the principal value of

3. A matrix A of order 3 × 3 has determinant 5. What is the value of | 3A | ?

4. For what value of x, the following matrix is singular ?

5. Find the point on the curve 2 3 2
y = x − x + , where the tangent is parallel to x-axis.

6. What is the angle between vectors
→ →
a & b with magnitude √3 and 2 respectively ? Given a . b = 3.
→ →

7. Cartesian equations of a line AB are.
Write the direction ratios of a line parallel to AB.

8. Write a value of ( )

x x
x
e d
3log 4

9. Write the position vector of a point dividing the line segment joining points A and B with position vectors

SECTION - B

11. Show that the function f : R→R defined by ( ) ∈

= x
x
f x ,
3
2 1
R is one-one and onto function. Also find the
inverse of the function f.
OR
Examine which of the following is a binary operation

for binary operation check the commutative and associative property.

12. Prove that

13. Using elementary transformations, find the inverse of

OR

Using properties of determinants, prove that
( )
3
2 2
2 2
2 2
ab bc ca
a ab b ab ab
a ac ac c ac
bc b bc c bc
= + +
+ + −
+ − +
− + +

14. Find all the points of discontinuity of the function f defined by

16. Evaluate
( ) ( )
( ) ( )
x
x x
x x
d
3 5
1 4
2 2
2 2
∫ + −
+ +

17. A water tank has the shape of an inverted right circular cone with its axis vertical and vertex lower most. Its semivertical angle is. Water is poured into it at a constant rate of 5 cubic meter per minute. Find the rate at
which the level of the water is rising at the instant when the depth of water in the tank is 10m.

18. Evaluate the following integral as limit of sum

19. Evaluate

20. Find the vector equation of the line parallel to the line
and passing through (3, 0, –4). Also(6)
find the distance between these two lines.

21. In a regular hexagon ABC DEF, if
→ → → →
AB = a and BC = b , then express
→ → → → → → → →
CD, DE, EF, FA, AC, AD, AE and CE
in terms of
→ →
a and b .

22. A football match may be either won, drawn or lost by the host country’s team. So there are three ways of
forecasting the result of any one match, one correct and two incorrect. Find the probability of forecasting at least
three correct results for four matches.

SECTION - C

23. Find the matrix P satisfying the matrix equation

24.A given quantity of metal is to be cast into a solid half circular cylinder (i.e., with rectangular base and semicircular
ends). Show that in order that the total surface area may be minimum, the ratio of the length of the cylinder to the
diameter of its circular ends is π ) π + 2 .

25. Sketch the graph of
Evaluate What does the value of this integral represent on the graph ?

26. Solve the following differential equation ( ) ,

27. Find the foot of the perpendicular from P(1, 2, 3) on the line
Also obtain the equation of the plane containing the line and the point (1, 2, 3)

28. Let X denote the number of colleges where you will apply after your results and P(X = x) denotes your probability
of getting admission in x number of colleges. It is given that

(a) Find the value of k.
(b) What is the probability that you will get admission in exactly two colleges?
(c) Find the mean and variance of the probability distribution.
OR
Two bags A and B contain 4 white 3 black balls and 2 white and 2 black balls respectively. From bag A two balls
are transferred to bag B. Find the probability of drawing
(a) 2 white balls from bag B ?
(b) 2 black balls from bag B ?
(c) 1 white & 1 black ball from bag B ?

29. A catering agency has two kitchens to prepare food at two places A and B. From these places ‘Mid-day Meal’ is
to be supplied to three different schools situated at P, Q, R. The monthly requirements of the schools are respectively 40, 40 and 50 food packets. A packet contains lunch for 1000 students. Preparing capacity of kitchens A
and B are 60 and 70 packets per month respectively. The transportation cost per packet from the kitchens to
schools is given below :
How many packets from each kitchen should be transported to school so that the cost of transportation is minimum ? Also find the minimum cost.

1. All questions are compulsory.
2. There is no overall choice. However, an internal choice has been pro vided in one question of
two marks, one question of three marks and all three questions of five marks. You have to
attempt only one of the choices in such questions.
3. Question numbers 1 to 5 are very short answer type questions, carrying one mark each.
4. Question numbers 6 to 12 are short answer type questions, carrying two marks each.
5. Question numbers 13 to 24 are also short answer type questions, carrying three marks each.
6. Question numbers 25 to 27 are long answer type questions, carrying five marks each.
7. Use of calculators is not permitted However, you may use log tables, f necessary.
8. You may use the following values of physical constants wherever necessary.
Q. 1. Write two properties of a material used as a suspension wire in a moving coil galvanometer. 1
Q. 2. Name the experiment which establishes the wave nature of a particle. 1
Q. 3. Write the S.I. unit for the activity of a radioactive nuclide. 1
Q. 4. The a.c. current gain of a transistor is 120. What is the change in the collector current in the
transistor whose base current changes by 1
Q. 5. Name the underlying principle of the working of an optical fibre. 1
Q. 6. Define ‘dielectric constant’ of a medium. Briefly explain why the capacitance of a parallel plate
capacitor increases, oii introducing a dielectric medium between the plates. 2
Q. 7. Why does a paramagnetic substance display greater magnetisation for the same magnetising
field when cooled? How does a diamagnetic substance respond to similar temperature changes? 2
Q. 8. Explain how electron mobility changes for a good conductor when (i) the temperature of the
conductor is decreased at constant potential difference and (ii) applied potential difference is
doubled at constant temperature. 2
Q. 9. A capacitor and a resistor are connected in series with an a.c. source. If the potential difference
across C, R are 120 V, 90 V rspectively and if the r.m.s. current of the circuit is 3 A, calculate the (i)
impedance, (ii) power factor of the circuit. 2
Or
An inductor 200 mH, a capacitor C and a resistor 10 ohm are connected in series with a 100 V, 50 s
-1
a.c. source. If the current and voltage arc in phase with each other, calculate the capacitance of the
capacitor. Q. 10. Draw the curve showing variation of binding energy/nucleon with mass number of
different
nuclei. Briefly state, how nuclear fusion and nuclear fission can be explained on the basis of this
graph. 2
Q. 11. Give r for the following:
(a) Rainbow is never observed on the surface of the Moon.
(b) The Sun looks reddish at sunrise and sunset as viewed from Earth. 2
Q. 12. The following figure shows the input waveforms (A, B) and the output waveform (Y) of a gate.
Identify the gate and write its truth table. 2
Q. 13. What are eddy currents? How are these minimised? Mention two applications of eddy
currents. 3
Q. 14. Draw the graphs showing the variation of photoelectric current with an ode potential of a
photocell for (i) the same frequencies but different intensities I1 > I2 > I3, of incident radiation, (ii) the
same intensity but different frequencies V1 > V2 > V3 of incident radiation.
Explain why the saturation current is independent of the anode potential. 3
Q. 15. State Faraday’s laws of electrolysis. Deduce the relation connecting Faraday constant,
chemical equivalent and electrochemical equivalent. 3
Q. 16. 4 cells of identical emf E, internal resistance r, are connected in series to a variable resistor.
The following graph shows the variation of terminal voltage of the combination with the current
output: (i) What is the emf of each cell used?
(ii) For what current from the cells, does maximum power dissipation occur in the circuit?
(iii) Calculate the internal resistance of each cell. 3
Q. 17. What is pulse modulation? Distinguish between pulse amplitude modulation and pulse
duration modulation by drawing suitable modulated signals. 3
Q. 18. Write any two criteria required for a detector of an optical communication system.
A photo-detector is made from a semiconductor having Eg = 0.73 eV. What is the maximum
wavelength which it can detect? 3
Q. 19. Using Gauss’ theorem, deduce an expression for the electric field intensity at any point due to
a
thin, infinitely long wire of charge/length 3
Or
Using Gauss’ theorem, derive an expression for the electric field intensity at any point outside a
charged spherical shell of radius R and of charge density
Q. 20. A metallic square loop ABCD of size 15 cm and resistance is moved at a uniform velocity
of v m/s, in a uniform magnetic field of 2 Tesla, the field lines being normal to the plane of the paper.
The loop is connected to an electrical network of resistors, each of resistance Calculate the
speed of the loop, for which 2 m A current flows in the loop. 3
Q. 21. Sketch a graph showing the variation of potential energy of a pair of nucleons as a function of
their separation. Write three characteristic properties of nuclear force which distinguish it from the
electrostatic force. 3
Q. 22. Explain, using Huygen’ principle, how diffraction is produced by a narrow slit which is
illuminated by a monochromatic light. Show that central maximum is twice as wide as the other
maxima and the pattern becomes narrower as the width of the slit is increased. 3
Q. 23. Draw a labelled diagram o the experimental set-up used by Hertz to produce electromagnetic
waves. Explain how the electromagnetic waves are detected. 3
Q. 24. Define the term electric potential due to a point charge.
Calculate the electric potential at the centre of a square of side having charges
at the four corners of the square. 3
Q. 25. Derive an expression for the magnetic field along the axis of an air-cored solenoid, using
Ampere’s circuital law. Sketch the magnetic field lines for a finite solenoid. Explain why the field at
the exterior mid-point is weak while at the interior it is uniform and strong. 5
Or
Explain with the help of a labelled diagram the working principle of a cyclotron.
Show that the cyclotron frequency does not depend on the speed of the particle. Write one of the
uses and point out one of the drawbacks of a cyclotron.
Q. 26. Draw a labelled circuit diagram of a transistor oscillator. Briefly explain its principle and state
how the oscillations are sustained. 5
Or
Draw the energy band diagrams of p-type, n-type semiconductors. Explain with a circuit diagram the
working of a full wave rectifier.
Q. 27. (i) Draw a labelled ray diagram of a compound microscope, showing the formation of image at
the near point of the eye.
(ii) A compound microscope uses an objective lens of focal length 4 cm and eye lens of focal length
10cm. An object is placed at 6 cm from the objective lens.
(a) Calculate magnifying power of the compound microscope, if the final image is formed at the near
point.
(b) Calculate the length of the compound microscope also. 5
Or
Draw a labelled ray diagram of an astronomical telescope, forming the image at infinity.
As astronomical telescope uses two lenses of powers 10 diopter, 1 diopter.
(i) State with reason, which lens is preferred as objective and eye-piece.
(ii) Calculate the magnifying power of the telescope, if the final image is formed at the near point.
(iii) How do the light gathering power and resolving power of a telescope change, if the aperture of
the objective lens is doubled ?
  #3  
24th March 2015, 03:29 PM
Unregistered
Guest
 
Re: CBSE 12 class exam paper of previous year

I am preparing for the CBSE class 12th exam. Will you please forward me question paper of CBSE class 12th of chemistry subject?
  #4  
24th March 2015, 03:38 PM
Super Moderator
 
Join Date: Apr 2013
Re: CBSE 12 class exam paper of previous year

As per your request, I am giving you question paper of the CBSE class 12th of chemistty subject. Hope it helps

Q. How does molar conductivity of a strong electrolyte vary with the dilution of electrolyte solution?

Q. Write the equation of the reaction involved in the preparation of Buna-S-rubber.

Q. What Define the term, homo-polymerization, giving an example.

Q. Name the two groups into which phenomenon of catalysis can be divided. Give an example of each group with chemical equation involved








Types of question: Marks for each question: No. of questions: Total marks
Long Answers (LA): 5: 3: 15 Maximum Marks
Value based question: 4: 1: 4 Maximum Marks
Short Answers-I: 2: 5: 10 Maximum Marks
Short Answers-II: 3: 12: 36 Maximum Marks
Very Short Answers: 1: 5: 5 Maximum Marks
Attached Files
File Type: pdf CBSE 12 class exam paper of previous year.pdf (3.79 MB, 571 views)


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