Class 1TH YEAR Federal Board 2009
Paper:Physics (Objective Type) Time
Allowed:
Max.Marks:
Note:Use this paper to write the answers to
the objective questions.No marks will be awarded for cutting,over-writing
or using a pencil.This paper must be tagged with the answer-book.
1- Insert the
correct option.
17
(i) What is the number of significant
digits in 0.0003?
(a) 01
(b) 02 (c) 03
(d) 04
(ii) A force F which makes an angle
with a smooth inclinedplane,acts on an object of mass m on the
plane,
acts on an object of mass m on the plane as shown in figure.What
is the magnitude of the
resultant
force on the object?
(a) F-mg
cos
(b) F sin --mg cos
(c) F
cos --mg sin
(d) F cos + mg sin
(iii) The motion of a ball rebounding
from a horizontal surface after being released from a point
above
surface
is described in the the sketch graph:
What parameter
of the ball does the Y-axis represent in the graph?
(a) Displacement
(b) Velocity
(c) Kinetic
(d) Acceleration
(iv) A stone is thrown from P and it
follows a parabolic path.This happens in the absence of air
resistance. The
highest point reached is T.Which of the following is true for the
vertical component
of the
stone?
(a) Same at
P as at T
(b) Greatest at T
(c) Greatest
at P
(d) Zero at T
(v) Choose the quantity referring to
linear motion that corresponds to moments of intertia in rotational
motion:
(a) Mass
(b) Kinetic energy
(c) Acceleration
(d) Momentum
(vi) When a gramophone turntable is switched
on, it rotates from rest and 5 sec , it attains an angular
velocity of
45rpm. What would be the angular acceleration?
(a) 0.9425 rad/S
2
(b) 0.4925 rad/S 2
(c) 0.09425
rad/S 2
(d) 0.9425 rad/S
(vii) An old communication satellite is replaced
by a new satellite which has twice the mass of the first.
Each of the
satellites has orbit time of 24hrs. What is the ratio of radius
of orbit of new satellite to
the radius
of orbit of old satellite?
(a) 2/1
(b) 1/1
(c) 1/2
(d) 2/1
(viii) Which of the following graphs shows the relation
between the acceleration of a body executing a
simple
harmonic motion and its displacement x from the centre of its path
?
(ix) What is the unit for the co-efficient
of viscosity ?
(a) Kgms-1
(b) Kgms
(c) Kgm-1s
(d) Kgm-1s-1
(x) When the length of simple pendulum
is doubled,What is the ratio of new frequency to the old
frequency
?
(a) 1
(b) 1
4
2
(c)
2
(d) 1
2
(xi) For which of the following state,the
equation PVm=RT ,is true ?
(a) Any mass
of an ideal gas
(b) One mole of a real gas.
(c) One mole
of an ideal gas. (d) One
Kg of a mono atomic gas.
(xii) A mixture of two gases at constant temperature
contains molecules of the kinds, the first of mass m1
and r.m.s speed C2. the second of mass m2 and r.m.s speed c2.What
is the value of g/c ?
(a) m1
(b) m2
m2
m1
(c) m1
(d) m2
m2
m2
(xiii) A body of mass m which is suspended from a
spring of fprce constant K, executes vertical simple
harmonic motion
with amplitude a. How can the maximum velocity of the body be expressed
?
(xiv) Which of the following will change in magnitude
when an earth satellite moves
from one
stable circular orbit to another higher stable circular orbit ?
(a) Angular
velocity.
(b) Centripetal acceleration
(c) Gravitational
potential energy (d) Liner orbital velocity.
(xv) Why do we use a laser for sending a signal
along amonomode fibre?
(a) The
laser has a very narrow band of wavelengths
(b) The
core has low rfractive index to laser light.
(c) The
light produced is faster than from any other source of light.
(d) The
electrical signal can be transferred quickly using a laser.
(xvi) Where is the final image formed when an astronomical
telescope is in normal adjustment ?
(a) At
the focal point of the objective
(b) at
infinity
(c) At
the focal point of the eye piece
(d) At
a distance equal to f + fe
(xvii) When two notes of frequencies f 1 and f 2
are sounded together,beats are formed, if f 1 > f 2
what
will be the frequency of beats ?
(a) F
1 + f 2
(b) 1/2 (f 1 + f 2 )
(c) f
1 - f 2
(d) 1/2 (f 1 - f 2 )
2. Attempt any fourteen
parts.
42
(1) Define radian and steratian.
(2) At what angle,with the horizontal
does the range of the projectile become half of its Rmax ?
(3) It is possible to distinguish between
a hard boiled egg and one which has not been boiled, by
spinning
the eggs on a flat table. Give a brief physical explanation of why
the behaviour of the eggs
must be
expected to be different? Which one spins more easily ?
(4) What are damped oscillations? What
happens to the energy in damping? Sketch a graph between
amplitude
and time,for damped and undamped oscillations.
(5) Explain,why sound travels faster
in warm air than in cold air ?
(6) Show that in SHM, the acceleration
is zero when the velocity is greatest and the velocity is zero
when
acceleration is greatest.
(7) Differentiate between magnifying
power and resolving power of an optical instrument.
(8) What is the disadvantageof using
step index fiber? How can this drawback be reduced?
(9) The uniform rectangular block shown
infigure is of height 40cm and 20cm wide.It is prevented
from sliding
.If the angle 0 is slowly increased,at what value of 0 will the
block topple over?
(10) Show that (A x B)2 + (A.B)2 = A2 b2
(11) A truck weighing 2500Kg and moving with
a velocity of 21 m/s collides.with a stationary car
weighing
1000kg.The truck and the car move together after the impact.calculate
their common
velocity.
(12) Find the numerical value of escape velocity
to show that a body with a speed equal to or greater
than that
value will never return.Give two assumptions necessary for this
result to be valid. what
are
the factors on which escape velocity depends?
(13) The minute hand of a clock is 3m long.What
is its mean angular speed?
(14) A ball tied to the end of a string is
swung in a vertical circle of radius r under the action of gravity,as
shown in the figure. What will be the tension in the string when
the ball is at the point A of the path
and its speed is v at this point?
(15) Prove that rate of flow, by volume,of
a fluid in a pipe remains constant.
(16) Fig (a) and (b) below shows how
the displacement x and the acceleration of a body vary with time
when it is oscillation with simple harmonic motion.What is the value
of T?
(17) A church organ consists of pipes,each
open at one end,of different lengths. The minimum length is
3mm
and the longest is 4m.calculate the frequency range of the
fundamental notes.
(18) Draw a proper, labeled ray diagram
of a compound microscope and explain the nature of images
formed
by the eyepiece and objective.
(19) A fixed mass of gas,undergoes changes
of pressure and volume as shown in the diagram.When the
gas is taken from state P to state R by the stages PQ and QR,8j
of heat is absorbed by it and 3j
of work is done.When the same resultant is achieved by stages PS
and SR, 1j of work is done.
Calculate heat absorbed in the stage,PSR.
Attempt any Two questions.
26
(3.a) Define projectile motion. Discuss its
vertical and horizontal motion.Derive formula for the height
time
of flight and range of the projectile.
9
(3.b) What are newton's rings? How are they
formed Draw a ray diagram to show the experimental
arrangement for observing Newton's rings. 4
(4.a) How is artificial gravity provided to
a space craft. What is the angular frequency of rotation of the
spacesship,which has radius R and it rotates around its own central
axis with angular speed . If
orbita l
radius of Earth is 4.23 x 10 4 km, then find the height of geostationary
satellite from the
equator.
7
(4.b) What are synchronous satellites? Give
at least two of its characteristics. What are its uses? 3
(4.c) How are these satellites used in communication
system? Why are microwaves used for this
purpose?
(5.a) Define entropy. Discuss it for reversible
and irreversible process.Explain why the entropy of the
universe always increase.
5
(5.b) Prove C p - C v = R
5
(5.c) Calculate the entropy change when 1.0
Kg ice at 0 C melts into water at 0 C.Latent heat of fusion
of ice Lf = 3.36 x 10 5 jkg-1
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