1st YEAR PHYSICS GUESS FOR EXAMINATION 2023
1st Year All Subjects Past Papers
1st Year Guess Papers
SHORT QUESTIONS
1)
2)
The
period of simple pendulum is measured by a stop watch. What type of errors are
possible in the time period?
3)
Does a
dimensional analysis give any information on constant of proportionality that
may appear in an algebraic expression? Explain.
4)
Three
students measured the length of a needle with a scale on which minimum division
is 1mm and recorded as (i) 0.2145 m (ii) 0.21 m (iii) 0.214m. Which record is
correct and why?
5)
The
vector sum of three vectors gives a zero resultant. What can be the orientation
of the vectors?
6)
Vector A
lies in the xy plane. For what
orientation will both of its rectangular components be negative? For what
orientation will its components have opposite sings?
7)
If one of
the rectangular components of a vector is not zero, can its magnitude be zero?
Explain.
8)
If A +B
=0, what can you say about the components of the two vectors.
9)
Two
vectors have unequal magnitudes. Can their sum be zero? Explain.
10)
How would
the two vectors of the same magnitude have to be oriented, if they were to be combined
to give a resultant equal to a vector of the same magnitude?
11)
If all
the components of the vectors, A1 and A2 were reversed,
how would this alter A1 x A2?
12)
Can a
body rotate about tis centre of gravity under the action of its weight?
3. Write answers
of any EIGHT questions. (8x2=16)
1)
An object
is thrown vertically upward. Discuss the sign of acceleration due to gravity.
2)
Can the
velocity of an object reverse the direction when acceleration is constant if
so, give an example.
3)
Explain
the circumstances in which the velocity v and acceleration a of a car are ;
(i) Parallel (ii) Anti-Parallel (iii) Perpendicular to one
another (iv) v is zero but a is not zero
(v) a is zero but v
is not zero
4)
Find the change in momentum for an object
subjected to a given force for a given time and state law of motion in terms of
momentum.
5)
Define
impulse and show that how it is related to linear momentum?
6)
At what
point or points in its path does a projectile have its minimum speed, its
maximum speed?
7)
A person
holds a bag of groceries while standing still, talking to a friend. A car is
stationery with its engine running. Form the stand point of work, how are these
two situations similar?
8)
Calculate
the work done in kilo joules in lifting a mass of 10kg (at steady velocity)
through a vertical height of 10m.
9)
A force F
acts through a distance L. the force is then increased to 3F, and then acts
through a further distance of 2L. Draw the work diagram to scale.
10)
An object
has 1J of potential energy. Explain what does it mean?
11)
When a
rocket re-enters the atmosphere, its nose cone becomes very hot. Where does
this heat energy come from?
12)
A boy
uses a catapult to throw a stone which accidentally smashes a greenhouse
window. List the possible energy changes.
4. Write answers of any SIX questions. (6x2=12)
1)
Explain
the difference between tangential velocity and the angular velocity. If one of
these is given for a wheel of known radius, how will you find the other?
2)
What is
meant by moment of inertia? Explain its significance.
3)
Show that
orbital angular momentum LO=mvr.
4)
State the
direction of the following vectors in simple situations; angular momentum
and angular velocity.
5)
Explain
how many minimum number of geo-stationary satellites are required for global
coverage of T.V transmission.
6)
Explain
what do you understand by the term viscosity?
7)
What is
meant by drag force? What are the factors upon which drag force acting upon a
small sphere of radius r, moving down through a liquid, depend?
8)
Why fog
droplets appear to be suspended in air?
9)
Two row boats moving parallel in the same
direction are pulled towards each other. Explain.
13)
Does
frequency depends on amplitude for harmonic oscillators?
14)
Can we
realize an ideal simple pendulum?
15)
What is
the total distance travelled by an object moving with SHM in a time equal to
its period , if its amplitude is A.
16)
What
happens to the period of a simple pendulum if its length is doubled? What
happens if the suspended mass is doubled?
17)
Does the
acceleration of a simple harmonic oscillator remain constant during its motion?
Is the acceleration ever zero? Explain.
18)
What is
meant by phase angle? Does it define angle between maximum displacement and the
driving force?
19)
Under
what conditions does the addition of two simple harmonic motions produce a resultant,
which is also simple harmonic?
20)
Show that
in SHM the acceleration is zero when the velocity is greatest and the velocity
is zero when the acceleration is greatest?
21)
Explain
the relation between total energy, potential energy and kinetic energy for a
body oscillating with SHM.
22)
What
features do longitudinal waves have in common with transverse waves?
23)
Is it
possible for two identical waves travelling in the same direction along a
string to give rise to stationary wave?
24)
A wave is
produced along a stretched string but some of its particles permanently show
zero displacement. What type of wave is it?
3. Write
answers of any EIGHT questions. (8x2=16)
13)
Explain
the terms crest, trough, node and
antinode.
14)
Why does
sound travel faster in solids than in gases?
15)
How are
beats useful in tuning musical instruments?
16)
As a
result of a distant explosion, an observer senses a ground tremor and then
hears the explosion. Explain the time difference.
17)
How
should a sound source move with respect to an observer so that the frequency of
its sound does not change?
18)
Under
what conditions two or more sources of light behave as coherent sources?
19)
Can
visible light produce interference fringes? Explain.
20)
In the
Young’s experiment, one of the slits is covered with blue filter and other with
red filter. What would be the pattern of light intensity on the screen?
21)
An oil
film spreading over a wet footpath shows colours. Explain how does it happen?
22)
What do
you understand by linear magnification and angular magnification? Explain how a
convex lens is used as a magnifier.
23)
Why would
it be advantageous to use blue light with
a compound microscope?
24)
One can
buy a cheap microscope for use by the children. The images seen in such a
microscope have colourededges. Why is this so?
4.Write answers
of any SIX questions. (6x2=12)
10)
If a
person was looking through a telescope at the full moon, how would the
appearance of the moon be changed by covering half of the objective lens?
11)
A
magnifying glass gives a five times enlarged image at a distance of 25cm from
the lens. Find, by ray diagram, the focal length of the lens.
12)
Why is
the average velocity of the molecules in a gas zero but the average of the
square of velocities not zero.
13)
Why does
the pressure of a gas in a car tyre increase when it is driven through some
distance?
14)
Specific
heat of a gas at constant pressure is greater than specific heat at constant
volume. Why?
15)
Give an
example of a process in which no heat is transferred to or from the system but
the temperature of the system changes.
A thermos flask containing milk as a system is shaken rapidly. Does the
temperature of milk rise?
LONG QUESTIONS
Attempt
any three questions. (8x3=24)
5. (a) Describe in detail the
process of addition of vectors by their rectangular components. (05)
(b) The magnitude of dot
and cross products of two vectors are 
and 6 vectors is respectively.
Find the angle
between the
vectors. (03)
6. (a) Establish relations for
(i) Height (ii) time of flight (iii)
range for a projectile launched with initial velocity 
with
angle 
. (05)
(b) Two Blocks of masses 2.0 kg and 0.50 kg are attached at the two
ends of compressed spring. The elastic potential
energy stored in the
spring is 10J. Find the velocities of
the blocks if the spring delivers its energy to the blocks
when released. (03)
7. (a) Define escape velocity
and describe in detail the
interconversion of potential and kinetic energy. (05)
(b)
A diver weighing 750N dives from a board 10m above the surface of a pool of
water. Use the conservation of
mechanical
energy to find his speed at a point 5.0 m
above the water surface, neglecting air friction. (03)
8. (a)
Define rotational K.E and use this concept to find the velocity of a disc and a
hoop at the bottom of an inclined
plane
when they are released from it’s top. (05)
(b)
What should be the orbiting speed to launch a satellite in a circular orbit 900
km above the surface of the Earth?
(take mass of the Earth as 6.0 x 1024
and its radius as 6400 km). (03)
9. (a)
Define Laminar flow and use it to establish the Bernoulli’s equation. (05)
(b)
An airplane design calls for a “lift” due to the net force of the moving air on the wing of about 1000
Nm–2 of wing
area.
Assume that air flows past the wing surface is 160ms–1, what is the
required speed over the upper
surface to
give
a “lift” of 1000Nm–2? The density of
air is 1.29kgm–3 and assume maximum thickness of wing to be
one metre.
(03)
5. (a)Establish the relations
for (i) Instantaneous velocity (ii)
Acceleration , for the projection of an object moving with
uniform velocity along a
circular path. (05)
(b)A Block of mass 4.0 kg is dropped from a height of 0.80 m on to a
spring of spring constant k = 1960 Nm–1, Find
the maximum distance through which the spring will be compressed. (03)
6. (a)Write a detailed note on
stationary waves produced in a stretched string and show that these waves are
quantized in terms of
frequency. (05)
(b)A train sounds its horn before it sets off from the station and an
observer waiting on the plateform estimates its
frequency at 1200 Hz. The
train then moves of and accelerates steadily. Fifty seconds after departure,
the driver
sounds the horn again and the plateform observer estimates the
frequency at 1140 Hz. Calculate the train speed 50
s after departure. How far
from the station is the train after 50s. (03)
7. (a)Describe in detail the
Young’s double slit experiment and establish a formula for fringe spacing and
also describe
it’s dependence upon
wavelength and slit spacing. (05)
(b)Light of wavelength 546
nm is allowed to illuminate the slits of Young’s experiment. The separation
between the
slits is 0.10 mm and the
distance of the screen from the slits where interference effects are observed
is 20cm. at
what angle the first
minimum will fall? What will be the linear distance on the screen between
adjacent maxima?
8. (a)Give a detailed account of
compound microscope and use a ray diagram to find it’s magnification and
compare it
with that of a simple
microscope. (05)
(b)The refractive index of
the core and cladding of an optical fibre are 1.6 and 1.4 respectively.
Calculate (i) the
critical angle for the
interface (ii) the maximum angle of incidence in the air of a ray which enters
the fibre an is
incident at the critical
angle on the interface. (03)
9. (a)Establish a formula for
pressure of a gas using the example of an ideal gas in a cubical container. (05)
(b)A Carnot engine whose
low temperature reservoir is at 7
has an efficiency of 50%. Ti is
desired to increase the
efficiency to 70%. By how
many degrees the temperature of the source be increased? (03)
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