# 11th physics &chemistry 2013 guess question paper

11th  Physics & Chemistry  2013 Guess& Sample Question Paper

Sample Paper – 2013
Class – XI
Subject –Physics

MM=90                                                                                                                 Class:- XI      Time= 3 hrs.                                                                                                 Subject:-Physics

General Instructions:-

1. All questions are compulsory. Symbols have their usual meaning.

2. Use of calculator is not permitted. However you may use log table, if required.

4. Q.No. 1 to 8 are of very short answer type questions, carrying 1 mark each.

5. Q.No.9 to 18 are of short answer type questions, carrying 2 marks each.

6. Q. No. 19 to 27 carry 3 marks each.

7. Q. No. 28 to 30 carry 5 marks each.

Q.1      You are given a thread and a meter scale. How will you estimate the diameter of the thread?

Q.2      How many cm are there in 100 nm?

Q.3      What is the ratio of A.B  to A x B when angle between A and B is 300?

Q.4      What would be the  pressure inside a water surface when you are at a depth of 140 m.

Q.5      An electric lamp of power 200 W is glowing for 30 minutes. Find the amount of energy consumed.

Q.6      State Newton’s universal law of gravitation and express it in vector form.

Q.7      Find the height above the earth surface where value of acceleration due to gravity is same as that at 20 m deeper inside the earth.

Q.8      A light body and heavy body have equal kinetic energy, which one have greater

momentum?

Q.9      What is the effect on viscosity of liquids when temperature is increased?

OR

Write down the dimension formula of velocity gradient..

Q.10    State Galileo’s law of odd number. If an object under free fall covers 49 m during the forth time interval. Find the distance covered during nineth time interval.

Q.11    Draw the Position – Time graph for following cases when

( i) Object is moving with positive acceleration.

( ii) An object is under free fall

Q.12    The escape velocity of a particle on earth is 11.2 km/s. What is its value for a planet having double the radius and 8 times the mass of earth?

Q.13    A car covers the first half of the distance between the two places at a speed of 40 km/h andsecond half at 60 km/h. Calculate the average speed of the car.

Q.14    Explain:   i) Why china plates are wrapped in in paper or straw pieces while packing?

ii) Bullet of equal mass are fired from a gun and a heavy rifle, in which the recoiling will be more and why?

Q.15    What do you mean by contact and non contact force. Give one example of each case.

Q.16    Derive the necessary relation for orbital velocity of a satellite.

Q.17    Explain with reason Why:

(a) A brass tumbler feels much colder than a wooden tray on a chilly day.

(b) The earth without its atmosphere would be inhospitably cold.

OR

Explain following with proper reason.

(a) Why blood pressure in humans is greater at the feet than at brain?

(b) Why does an engine require more time / kicks to get started during winters?

Q.18    State Hooke’s law. Explain Stress – Strain curve of a material when subjected under extended load.

Q.19    State and prove Work- Energy Theorem. Find out the work done by a force, which increases the

velocity of 20 kg mass from 12 m/s to 90 km/h in 10 seconds.

Q.20    Two physicists, both of mass 50 kg, climb up identical ropes suspended from the ceiling of a gymnasium. The ropes  are 15 m long. Physicist 1 reaches the top twice as quickly as Physicist 2 does.  After reaching at top, they argue about who did more work agaists gravity:

Physicist 1:

“ I did more work fighting gravity, because I was overcoming gravity more quickly. Your climb was lazier, and therefore, you did less work.”

Physicist 2:

“ No way. I did more work fighting gravity, because I spent more time climbing the rope.  Since we both ended up at the same height, but I spent more time getting there, I had to work harder .”

i) Which physicist, if either, did more work against gravity while climbing from floor to ceiling ?                        a)Physicist 1 did more work                           b)Physicist 2 did more work                                                                             c)Both did the same work                              d) Neither physicist did any work

ii) Physicist 2 started at rest from the f loor and ended at rest near ceiling . Which of the following best expresses the net energy transfer during this process?                                                                                                                a)Chemical to kinetic                                      b)Chemical to potential                                                                         c)Kinetic to chemical                                      d)Kinetic to potential

iii) Physicist 1 started falling from ceiling  onto a heavily-padded cushion, safely coming to rest. Which of the following best expresses the net energy transfer during this process?                                                                                a)Chemical to kinetic to heat                          b)Potential to chemical to heat                                                                    c)Potential to kinetic to heat                           d)Kinetic to potential to chemical

Q.21    The displacement (in metre) of a particle moving along x-axis is given by x = 20t + 5t2 . Calculate

(i)                 the instantaneous velocity at t = 2 seconds.

(ii)               average velocity between t = 4s & t = 7s

(iii)             Instantaneous acceleration.

Q.22    a) Prove that    log 160 = 3 log 4 + 2 log 10 – log 40

b) Evaluate ( 5 x + 4x2 ) dx

c) Define dot product of two vectors. Prove that    .  = 0 .

Q.23    What do you mean by acceleration due to gravity? Derive the necessary relation for variation of g with depth.

Q.24    Define force. Write its dimensional formula. Prove that F= m x a, using Newtons II law.

Q.25    A man of mass 70 kg stands on a weighing scale in a lift which is moving

a) upwards with a uniform speed of 10 m/s

b) downwards with a uniform acceleration of 5 m/s2

c) upwards with a uniform acceleration of 5 m/s2

What would be reading on the scale in each case?

Q.26    State Pascal’s law. How it can be used in Hydraulic brakes. Explain its working with diagram.

Q.27    Define and derive the term associated with projectile motion:                                                                                            i) Time of flight                                                                                                                                             ii) Horizontal range.

Q.28   i) What do you mean by friction? Write its types.                                                                                                            ii) How does it vary with weight of the object?                                                                                                                                           iii) How does it vary with area of contact?                                                                                                                                  iv) What happens to force of friction if two surfaces in contact are made extremely smooth?                                                              v) Write any two methods to reduce the friction.

OR

Explain the bending of a cyclist during taking a circular turn. Calculate the angle through which the cyclist bend with the vertical when he crosses the circular path 34.3 in circumference in √22 seconds.

Q.29  State and explain the principle of law of conservation of energy.Prove it for freely falling bodies.

OR

Show that in a head-on collision between two balls of equal masses moving along a straight line, the balls simply exchange their velocity.

Q.30  (a) What is angle of contact? When it is obtuse ? When it is acute?

(b) Define terminal velocity of a fluid. Derive the expression for it.

OR

State and prove Bernoulli’s theorem. Explain any one application of it.

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CHEMISTRY

Guess Paper – 2013
Class – XI
Subject -
CHEMISTRY
MAX MARKS=90

………………………………………………………………………………………

General instructions:

All questions are compulsory.

Marks for each question are indicated against it.

Questions number 1to 8 are very short –answer questions, carrying 1 mark each. Answer these in one word or about one sentence each.

Questions number 9 to18 are short –answer questions, carrying 2 marks each. Answer these in about 30 words each.

Questions number19 to27 are short –answer questions, carrying 3 marks each. Answer these in about 40 words each.

Questions number28 to30 are long-answer questions of 5 marks each. Answer these in about 70 words each.

7 Use log tables if necessary. Use of calculators is not permitted

QUESTIONS:

1.Define molality.                                                                                                                               (1)

2.Calculate the number of lines when an electron jumps from 6th level to 2nd level.                            (1)

3. If two discharge tubes A and B are filled with Hydrogen and oxygen respectively, will the electrons and gaseous cations be the same?  Justify your answer.                                                                                          (1)

4. Which of the two is paramagnetic:V+4  or V+5 and why?                                                                 (1)

5 How cathode rays are originated in the discharge tube and how their origin differs from the origin of anode rays?

6 When is a cation highly polarizing? Which alkali metal has the highest polarizing power?               (1)

7.Why is KO2 paramagnetic?                                                                                                               (1)

8 Potassium and Caesium are used in photoelectric cells. Why?                                                                      (1)

9 Concentrated sulphuric acid is 98% H2SO4 by mass and has a density of 1.84g/cm3. What volume of concentrated acid is required to make 5 litres of 0.5 M H2SO4?                                                                                (2)

10 How many atoms and molecules of oxygen are present in 5.6 litres of oxygen at STP?                 (2)

11 Define Empirical formula and molecular formula.                                                                                     (2)

12 Calculate the frequency and wavenumber of a radiation with wavelength 480nm.                                    (2)

13 Write any four properties of d-block elements.                                                                              (2)

14What are isoelectronic species? Arrange the following in increasing ionic radii.                              (2)

P3-, S2-, Cl-, K+, Ca 2+

15 What is diagonal relationship? Which elements in the group 1 and 2 show diagonal relationship with which elements? What is the reason?                                                                                                            (2)

16 Write reactions involved in the manufacture of washing soda by Solvay process.                       (2)

17 A large number of fish are suddenly found floating dead on a lake. There is no evidence of toxic dumping but you find an abundance of phytoplankton. Suggest and explain a reason for the fish kill.                                            (2)

18 What do you mean by ozone hole? What are its consequences?                                                                (2)

19 Mothballs contain 93.71% carbon and 6.29% hydrogen. If its molecular mass is 128g/mol, calculate its molecular formula.                                                                                                                                                     (3)

20What do you understand by Heisenberg uncertainty principle?  On the basis of this principle explain why electron cannot exist inside the nucleus? (radius of nucleus=10-15m, mass of electron=9.1X10-31 kg,h=6.626X10-34 Js. (3)

21 Define and name quantum numbers. What information about electron is obtained from each quantum number?                                                                                                                                                      (3)

22 Define Hund’s rule of maximum multiplicity. Write electronic configuration of Chromium (Cr) and Copper(Cu). At No of Cr=24, Cu=29                                                                                                               (3)

23 What is shielding effect? Which properties of elements are affected by shielding effect? Give example.(3)

24 What is atomic radius? What are its types? Which one of them is largest and why?                                (3)

25 Explain why Li and Be show anomalous behavior in their groups?                                                          (3)

26 Explain why?                                                                                                                                             (3)

(i) Solutions of alkali metals in liquid ammonia are coloured, paramagnetic, conducting and reducing.

(ii) LiCl is covalent whereas NaCl is ionic.

(iii) LiF is insoluble whereas other alkali metal fluorides are soluble.

27 Define water pollution. What is BOD and COD? What is the significance of BOD?                             (3)

28 (a) Define photoelectric effect.                                          (1)

(b) What is de-broglie equation? What is its significance?  (2)

(c) What is (n+l) rule?   (1)

(d) What is spectrum?   (1)

OR

(a) Define Black Body radiations.                                                                                                                (1)

(b) Define Aufbau principle.                                                                                                                        (1)

(c) Write differences between orbit and orbital.                                                                                         (3)

29 What is ionization enthalpy? What are the factors which affect ionization enthalpy? Explain why ionization enthalpy of Al is less than that of Mg and ionization enthalpy of oxygen is less than that of nitrogen which is against the general trend?                                                                                                       (5)

OR

What is electron gain enthalpy? What are the factors which affect electron gain enthalpy?

Explain why electron gain enthalpy of fluorine is found to be less than the electron gain enthalpy of chlorine ?                                                                                                                                                                            (5)

30  Explain why?

(i) Beryllium chloride fumes in moist air.

(ii) Magnesium oxide is used as a refractory material.

(iii) Solubility of hydroxides of alkaline earth metals increases from top to bottom in the group.

(iv) Alkaline earth metals are weaker reducing agents than alkali metals.

(v) LiOH decomposes on heating whereas hydroxides of other alkali metals do not.

OR

(a) Arrange the following as specified:                                                                                                          (2)

(i) MgO, SrO, K2O and Cs2O(increasing order of basic nature)

(ii) LiCl, LiBr,LiI (decreasing order of covalent character)

(b) How would you distinguish between Magnesium and calcium?                                                             (1)

(c) Why Li and Be cannot expand their covalency beyond 4?                                                                       (1)

(d) Why BeCl2 and AlCl3 are used as Lewis acids?                                                                                      (1)

sample paper - 2013

Subject: Chemistry

Class XI

MM: 70                                                                                     Time:3.00 Hr.

General Instructions :

1.         All questions are compulsory.

2.         Questions no. 1 to 8 are very short answer questions and carry 1 mark each.

3.         Questions no. 9 to 18 are short answer questions and carry 2 marks each.

4.         Questions no. 19 to 27 are also short answer questions and carry 3 marks each.

5.         Questions no. 28 to 30 are long answer questions and carry 5 marks each.

6.         Use log tables if necessary, use of calculators is not allowed.

1.         State the relationship between :                                                                                  1

(i) Empirical and molecular formula.

(ii) Molecular wt. and vapour density.

2.         Write IUPAC name for;                                                                                             1

OH

3.         Which one of the following atomic orbitals is not possible ? Why ?                          1

(i) n = 3, l = 1, m = –2             (ii) n = 4, l = 0, m = 0

4.         What is the significance of van der Waal's constant 'b' ?                                           1

5.         What is inductive effect ?.                                                                                          1

6.         State why heat changes in chemical processes are indicated as enthalpy changes and not internal energy changes ?                                                                                                1

7.         What is the condition required for the precipitation to occur ?                                  1

8.         Give an example of a b–elimination reaction.                                                            1

9.         A compound contains 4.07 % hydrogen, 24.27 % carbon and 71.65 % chlorine. It's molar mass is 98.96 g . Deduce  the empirical and molecular formulae.                                    2

[ At. masses : H = 1 ; O = 16 ; Cl = 35.5 ]

10.       How would you separate a mixture of ethylene, acetylene and ethane ?                   2

11.       Explain the significance of the terms ‘isolated gaseous atom’  and  ‘ground state’ while     defining ionization enthalpy and electron gain enthalpy.                                      2

12.       State why :                                                                                                                  2

(a) In any period, the alkali metal has lowest ionization energy.

13.       (a) Write an expression to calculate angular momentum of an electron ?

OR

(a) Which quantum number does not follow from the solution of Schrodinger wave

equation ?

(b) An electron has s = + ½ and m = -1, it cannot be present in which of the orbitals and                      why ?

14.       Differentiate between primary and secondary pollutants.                                         2

15.       The following system is in equilibrium ;                                                                     2

SO2Cl2 + Heat                  SO2 + Cl2

What will happen to the temperature of the system if some Cl2 into it at constant volume ?            Give reason.

16.       Write the conformations of ethane and compare their stability.                                 2

17.       Account for the following :                                                                                        2

(a) Alkali metals are used in photoelectric cells.

(b) There is a very large difference between first and second ionization energies of alkali

metals.

18.       Explain why :                                                                                                              2

(i) B––X bond length in BX3 is shorter than theoretically expected values.

(ii) BCl3 has a higher stability than TlCl3.

19.       Write down chemical equations (only) corresponding to the following :                  3

(i) Friedel-Craft's reaction

(ii)

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