MBOSE Class 11 Question Paper 2019 for Physics

Total No. of Printed Pages ––11 (2)
HS/XI/Sc/Ph/19

2019 short answer questios of two marks each. Section C
contains nine short answer questions of three marks
PHYSICS each. Section D contains one value based question of
four marks each and Section E contains three long
( Theory )
answer questions of five marks each.

Full Marks : 70
(e) There is no overall choice. However, an internal choice
Time : 3 hours has been provided in one question of two marks, one
question of three marks and all the three questions
The figures in the margin indicate full marks for the questions of five marks weightage. You have to attemt only one
of the choices in such questions.
General Instructions :

(a) 15 minutes time has been allotted to read this question (f) You may use the following values of standard physical
paper. The question paper will be distributed exactly constants wherever necessary.
15 minutes before the commencement of the
examination, the students will read the question paper
(i) Acceleration due to gravity, g = 9.8 ms 2
only and will not write any answer on the remaining
empty spaces on the question paper during this period. (ii) Radius of the earth, Re = 6400 km

(b) All questions are compulsory. There are 30 questions (iii) Universal gas constant, R = 8.314J mol–1 K–1
in all.
(iv) Boltzmann constant, KB= 1.381 x 10–23 J K–1
(c) This question paper has five sections: Section A
(I and II) Section B, Section C, Section D and
(v) Velocity of light C = 3x 108ms–1
Section E.

(d) Section A–I contains five multiple choice questions of (vi) Young’s modulus of steel Y = 2.0 x 1011Nm–2
one mark each, Section A–II contains very short answer
questions of one mark each. Section B contains seven (vii) Avogadro number, N = 6.023 x 1023 per gram mole.

HS/XI/Sc/Ph/19 HS/XI/Sc/Ph/19

(3) (4)

SECTION – A – I (c) both the mass of satellite and radius of the orbit.

( Multiple choice questions ) (d) neither the mass of satellite nor the radius of
the orbit.

1. The dimensional formula for latent heat is 1
4. An ideal monatomic gas is taken round the cycle
(a) [ M o L2T 2 ] ABCDA as shown in the P –V indicator diagram below: 1

(b) [ ML2T 1 ] The work done during the cycle is
(a) PV P
(c) [ MLT 2 ] B(2P,V ) C(2P, 2V )
(b) 2PV
(d) [ ML2T 2 ]
PV
(c) A D(P, 2V)
2 (P,V)
V
(d) Zero
2. The length of a rod is (11.05  0.05)m. What is the total
length of two such rods? 1

(a) (22.1  0.05)m 5. A ray of light is incident at the glass-water interface
at an angle of incidence i, if it emerges finally parallel
(b) (22.10  0.05)m to the surface of water, then the refractive index of
glass  g would be 1
(c) (22.1  0.05)cm

(d) (22.10  0.10)m 4
(a) sin i
3
water
1 r
(b) r
3. The time period of an earth satellite in circular orbit is sin i
independent of 1 glass
4 i
(c)
(a) the mass of the satellite 3
(d) 1
(b) radius of its orbit.

HS/XI/Sc/Ph/19 HS/XI/Sc/Ph/19

(5) (6)

SECTION – A–II 12. The position of an object is given by the equation
x = 2 + 2.5 t2, where the constants 2 and 2.5 indicate
( Very short answer type questions ) the displacement and constant acceleration of an
object respectively. Find the average velocity between
6. “Multiplying any vector by a scalar”. Give reasons if t = 2 sec and t = 4 sec by using calculus. 2
this algebraic operation is meaningful. 1
13. What is a conservative force? Mention its various
properties. 2
7. Write an expression showing the variation of
acceleration due to gravity with height above the
surface of the earth. 1 14. Two identical ball bearings in contact with each other
and resting on a frictionless table are hit head on by
another of identical ball bearing moving initially with
a speed V. If the collision is elastic which of the
8. Give a graphical representation for a body which is
following diagrams is a possible result after collision.
vibrating with a time period T. 1
Support your answer with valid equation. 2
Before Collision  After Collision
9. State the law of equipartition of energy. 1 V
1 2 3 (1)
2
V 0
1 V 2 3 1 2 3 V (2)
10. State Stokes’ law of viscosity. 1
V 0 V 0
1 2 3 V (3)



SECTION – B 3

( Short answer type questions )
15. In a hydrogen atom, an electron revolves around the
o
11. The length of a given steel rod as measured by the nucleus in a circular orbit of radius 0.45 A with a speed
students are 3.14cm, 3.12cm and 3.15cm. Calculate of 3.110 6 ms 1 . Find its angular momentum. 2
the mean absolute error of these lengths. 2

HS/XI/Sc/Ph/19 HS/XI/Sc/Ph/19

(7) (8)

16. Either 21. Either,
State any two Kepler’s laws of Planetary motion. 2
Show that the torque acting on a particle is equal to
OR, the rate of change of angular momentum. 3
What are Geostationary satellites? Name atleast one
OR
such satellite owned and used by India. 2
Derive the expression for the kinetic energy of a
rotating body in terms of the moment of inertia of
17. Using the expression for escape velocity from the
the body. 3
surface of the planet earth, calculate the numerical
value of escape velocity of a body of mass 10kg from
the surface of the earth. 2
22. Explain the basic requirement of heat engines with
the help of a schemetic diagram representation.
SECTION –– C 2½ + ½ = 3

Short answer type – (3 marks each)
23. Derive an expression for the work done during an
18. Obtain the equation of maximum range of a projectile adiabatic process. Give the necessary P-V indicator
projected at an angle  with the horizontal at an initial diagram. 2½ + ½ = 3
velocity V0. 3

19. (a) Derive an expression for stopping distance for 24. What is Doppler’s effect? Derive an expression for the
vehicles. apparent pitch heard by the listener at rest when
(a) the source of sound is approaching the listener
(b) A car moving along a straight highway with speed (b) the source of sound is receding away from the
of 126km h –1 is brought to rest within a distance listener. 1+1+1=3
of 200m. What is the retardation (assumed
uniform) of the car and how long does it take for
the car to stop. 3
25. The value of G in CGS system is 6.67  10 8 dyne
20. Prove the work-energy theorem for a variable force. cm2g 2 . Use dimensional analysis to find the value of
Mention one important uses of this theorem. 3 G in SI unit. 3

HS/XI/Sc/Ph/19 HS/XI/Sc/Ph/19

(9) ( 10 )

26. A 4kg mass is attached to a spring of spring constant (b) Torricelli’s barometer used mercury. Pascal
400 Nm–1. It is made to vibrate on a frictionless rod. duplicated it by using French wine of density
The mass is displaced through a distance of 10cm from 984kg m 3 . Determine the height of the wine
the equilibrium position and then released. Calculate column for normal atmospheric pressure [Take
(a) the time period of oscillation (b) the maximum speed normal atmospheric pressure P  1.013  105 Nm2 ] 2
of vibration (c) the maximum acceleration of the
Or
attached mass. 1+1+1=3
(a) Define heat. Draw a simple pictorial labelled
diagram to represent the different modes of
SECTION –– D transference of heat.

Value based question– (4 marks ) (b) The co-efficient of volume expansion of glycerin
is 4 .5  10 5 K 1 . What is the fractional change in
its density for 30oC rise in its temperature.
27. A dead snake remain submerged at the bottom of the
water tank and could not be visible to the observer
outside the tank. This dead snake could be made
visible only by pouring more water into the tank so
that the apparent position of the dead snake is raised 29. (a) Derive the equation of the time period of a simple
due to refraction of light. If the height of the tank is pendulum.
5 m, what should be the level of water to be poured
(b) Show that the length of a seconds pendulum is
into the tank so that an observer at a particular
nearly 1m.
position can see the dead snake only when its position
is raised by 1m above the bottom of the tank? 4 Or

(a) Derive the equation of refractive index of a glass
SECTION –– E prism in terms of the angle of minimum deviation.
(Long answer type) (b) A ray of light passing through a glass prism of
refracting angle 60 0 undergoes a minimum
28. (a) Explain briefly the working principle of a deviation of 300. Calculate the velocity of light in
hydraulic lift. State the law involved. 2 + 1 =3 glass.

HS/XI/Sc/Ph/19 HS/XI/Sc/Ph/19

( 11 )

30. Either
What is banking of roads? What is the need for banking
of a road? Obtain an expression for the maximum
speed with which a vehicle can safely negotiate a
curved road banked at an angle  . The co-efficient of
friction between the wheels and the road is μ .
1+1+3=5
Or

Show that the equation of path of a projectile is a
parabola. Obtain an expression for the horizontal
range of a projectile. 2½ + 2 ½ = 5



HS/XI/Sc/Ph/19