# 9th class Physics paper 2018 federal board

9th class paper in written form you can find only here this data is original its 100%tested 9th class physics paper 2018 federal board

## SECTION

SECTION — 0 (Marks 26)
Note: Attempt any TWO questions. All questions carry equal marks. (13 x 2 = 26)
Q4a4 ia. Define absolute gravitational P.E and derive its relation. {1+5)
b. What are non-conventional energy sources? Discuss any two. (1+3)
c. How large a force 1s required to accelerate an electron (m= 9.1«10 “Ay ) from rest to speed of
210° ms”! through Sem ? (03)
as a Disouss SHM and uniform circular motion and derive an expression for displacement and
acceleration in terms of w . (06)
b. Discuss energy conservation in SHM. (04)
c. What should be the length of simple penaulums whose period is isec at a place where x ~ 9.8ms? (03)
aé ia What is Carnot engine? Disuses its working and find out efficiency of Carnot engine. (14441)
b. Show that the pressure exerted by gas is directly proportional to the average translational
K.E of the gas molecules (04)
e 336.7 of energy is required to melt Ig of ice at 0°C . What is the change in entropy of 30g of
water at 0°C as it is changed to ice at 0°C by a refrigerator? (03)
-— 1HA 1808 (ON-—

9th class Physics paper

### SECTION

SECTION — © (Marke 2%) –
iGhanters 1 to @)
Q@2 Answer any SEVEN parts. All parts carry equal marks. (7 x3 = 21)
. [Fxt y .
) Check the correctness of the retation V = zr . where v is apeed, F is tension in the string
m

and m is mass.

(i) Why do we find it useful to have two units fer amount of substance, the Kilogram and mole?
Oiscuss briefty

(ii) Name the three different conditions that could make 4 x 4 =0

(iw) Gventhat 4-/-2j+3h and B= 3i~4k _ Find the projection of 4 on &

(vy) Oefina momentum and impulse and find their retation.

(vi) Oerve an expression for the range of a projectile.

(wi) Calculate the work done in Kilo Joules in iiftng a mass af 20kg at steady velocity through a
vertical height of 20m .

(wii) Define Power with its unit and show that P= FF .

(ix) What is meant by moment of inartia? Discuss its significance briefly.

(9 Exptain oriefty the working of a carburettor of a motorcar using Bernoulli’s principte.

SECTION — ¢ (Marka 21)
{Chapters 7 to 11)
Q@3 Answer any SEVEN parts. All parts carry equal marke. {7 x3 = 21)

0] In relation te SHM explain briefly the equations:
a) ¥ = Asin(wt +9) b) a=-wx

(i) A simple pendulum is 50cm long. What will be its frequency of vibration at a place where
2298 ms 7

(iit) How are beats useful in tuning a musical instrument?

(tv) Why stars moving towards the earth show a blue shift and that are moving away show a red
shift?

iv) Can visible light give interference fringes? Explain briefly.

(vd Explain briefly whether the Young’s Experiment is an experiment for studying interference or

9th class Physics paper

#### your answers neatly and legibly.

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your answers neatly and legibly.
SECTION ~ 8 (Marks 21)
{Chapters 1 to 6)
Q.2 Answer any SEVEN parts. All parte carry equal marks. (7 x3 = 21)
a Show that the expression 1, =\,+ar is dimensionally correct. where «, is the velocity at 1-0
and v, is the velocity at time ¢
(u) Give the drawbacks to use the petiod of pendulum as a time standard.
(iin) Hf one of the rectangular components of vector is not zero. Can its magnitude be zero? Explain
briefly.
(iv) Define unit vector and find the unit vector in the direction of vector 45 41 +3)
(v) Can the velocity of an object reverse the direction when acceleration is constant? If so, give an
example
qi) Find the angle of projection of projectile for which its maximum height and horizontal range are
equal
(vii) An object has L/ of P.E. What does it mean?
(vn) A girl drops a cup form a certain height, which breaks. What energy changes are involved?
(v9) What ts meant by angular momentum? Show that Lo = mvr .
(x} A person is standing near a fast moving train. Is there any danger that he will fail towards t?
Explain briefly
SECTION – C (Marke 21)
{Chapters 7 to 11)
Q.3 Anewer any SEVEN parts. All parts carry equal marks. (7 x3 = 21)
@) Does the acceleration of a simple harmonic oscillator remain constant during #8 motion? Is the
acceleration ever zero? Explain bnetly.
(ii) Define resonance and name any two phenomena in which resonance is involved
qu) Why does sound travel faster in warm air than in cold air? Explain briefly
{iv) Define the terms crest, tough and node.
{v) Define coherent sources. Under what conditions two sources of light behave as coherent
sources?

### Answer Sheet 9th class Physics paper

Answer Sheet according to the instructions given there. Each part carries one mark.
1) For an ideal gas, the internal energy is directly proporbonal to:
A. Volume 8. Density Cc. Pressure D Temperature
2) Thermal pollution is an inevitable consequence of:
A First law of thermodynamics. B. Newton’s third law
Cc. 2nd law of thermodynamics. o. Pascal’s law
3) The Prefix one peta is:
A. 19° 8 lo” Cc. 10” 0 10%
4) Counter clockwise Torque is:
A Zero 8 Infinite Cc. Negative 0. Positive
5) It A-:ai and B= aj then:
A ABroa 8. ABx0 c. ABza D ABs
6) The motion and rest are:
A Discrete 8. Random Cc. Absolute 0 Relative
7) The fuel consumed by a typical rocket to provide enough upward thrust to overcome gravity Is
A. lo00dkghr |B. 10000égs” c. 16000 gs” 0 10000kg rnin
8) When the angle between force and displacement is greater than 90°. the work done is.
A Negative 8. Positive c. Maximum 0. Zeta
9) Which of the following is non-conservative force?
A Electric force 8. Elastic spring force
c. Gravitational force ob. Normal force
10) SI unt of angular momentum is:
A Nm 8. Radian c. Ns D. as
1t) Bernoulli’s equation is based on the iaw of conservation of:
A Charge B. Momentum c. Mass 0. Energy
12) \f radius of the droptet is doubled, the terminal velocity increases:
A. Four tmes 8 Eight times Cc. Two times 0 Three times
13) Tuning of a radio is an example of:
A Musical resonance 8. Magnetic resonance
c. Mechanical resonance 0, Electneal resonance
14) lta transverse wave, travelling in a rarer medium, is reflected from a denser medium, it undergoes a path
difference of:
A a 8 A c. 4 D A
2 8 4
15) A diffraction grating has 5000 lines per cm. Its grating element is:
A. 210° em 8. 0.2x 10° cer c. 200 x10? car 0. 20« 10 ‘co
16) For light of wavelength 2 through a lens of diameter D, the resolving power is grven by