# 1st year Physics Paper 2019 Federal Board

NOTE: Answer any seven parts each from sections B and C and any two questions from section D on the 1st year physics paper

• ‘separately provided answer book. Use supplementary answer sheet Le. Sheet-8 if required. Write
_ eS
SECTION — B (Marke 21)
— {Ghapters 1 to 5}
_ Q.2 Answer any SEVEN parts. All parts carry equal marks. @ x35 21)
@ ‘Show shat the famous Einstein’s equation £ = amc? is dimensionally conséstent
— (ii) What does word micro’ signify in the words ‘microwave oven’?
_ (itl Waite down the steps for the addition of vectors by rectangular components method.
(w) Explain how cranes are able to lift the very heavy load without toppling?
7 (v) Aeroplane while horizontally drops a bomb when reaches exactly above the target, but missed @.
_ Explain briefty.
(vi) State how impulse is related to bear momentum.
— «
(vi) Show that H, = im Ye ¢as@)Ad, for a variable force.
_ ee
(viii) Differentiate between Solar energy and Wind energy
~ (x) Establish @ relation between Linear velocity(v) and Angular velocity (w)
= (x) Show that orbitat velocity, v « —L
vr
• 1st year physics paper
SECTION — C (Marks 21)
— {Chaptera 6 to 10)
0.3 Answer any SEVEN parts. All parts carry equal marks. {7 x3 = 21)
_ re) What is meant by aerofoils? Explain beefy.
_ «ay How do pulsations in puise show ihe heartbeat?
ii) Differentiate between free and forced oscillations.
~ (iy Give two applications in which resonance plays an important role.
— (4) Why do sound waves travel faster in solids than in gases?
(ay What is the difference between progressive and stationary waves?
(4) Ina Michelson interferometer a second giass plate is also used. Why?
— (vm) What is meant by dual nature of light? Explain briefty.
_ fix) Offferentiate between Reversible and irreversible processes.
(a White the imitations of first ta of thermodynamics.
SECTION — D (Marks 28)
~ Note: Attempt any TWO questions. All questions cerry equel market. (13×2= 26)
_ adoia efine projectie motion wih figure. Also derive mathematical equations for maxima
height stained, time of fight and range of projactite. (268)
a b. A ball of mass 100 g is thrown vertically upward at a speed of 25ms”’. If no energy is lost,
otermine the height # would reach. If the bal only rises to 25 m, calculate the work done against
— am resistence. Also calculate the force of friction. (05)
_ asia Derive equations for kinetic and potential energies of a body of maas m executing S.H.M. (07)
b Acar ia moving at 20ms”‘ along a straight road with its S00 horn sounding. You are standing
_ at the road side. What frequency do you hear as car is.

#### SECTION – 6 (Marks 21) (Chapters 1 to 6)

1st year physics paper

~ Q.2 Anewer any SEVEN parts. All parte carry equal marks. (7 x3 =21)
= Ww Define the number ec and show that 2 radian = 360°
(ii) Give the draw backs to use the period of a pendulum as a time standacd.

(iti) Briefly explain how cranes are able to lift very heavy load without toppling?
— (ivy Briefty explain why do buses and heavy trucks have large stearing wheets?
__ (vy What is head-on collision? Exptamn briefty with an exampie.

(4) Define elastic and inetastic collisions.
~ (vi) Why are energy savers used instead of normat bulbs?
_ (vai) Does a hydrogen filled balloon possess any P E? Explain briefly.
_ (iy) Establish a relation between linear acceleration (a) and angular acceleration(a)
_ (x) ‘Why is the fly wheel of an engine made heavy in the nm?
_ SECTION – © (Maries 21)

iGheaters 6 t0 10)

~ Q3 Answer any SEVEN parte. All parte carry equal maria. (7 x3 2 21)
— 0] Describe the working of an engine carburetor and paint spray.
_ ) Smoke rises in 2 chimney faster when a breeze is blowing. Exptain briefly.

(ii) Is there any connection between ‘F’ and ‘x’ in mass spring system? Explain briefly.
~ (Wy) A singer holding a note of right frequency. can shatter a glass? Explain brisfty.
_ (wy ts # possibte for an object which is vibrating transversely to produce sound wavee?

(vi) Why 40 sound waves travel faster in the solide than in gases?
~ (vi) Can we apply Huygen’s principle to radar waves?

• (vil) A soap bubble fooks black when it bursts. Why?
_ tex) ‘Write the limitations of first law of thermodynamics.

## objective

oo Entropy is often called as “time arrow’. Expkain briefy.
— SECTION — D (Maris 26)
_ Note: Attempt any TWO questions. All queetions carry equal marks. (13 x2 = 26}
_ Qa4s4oia State and explain Bemoulf’s equation. Explain any three applications of Bemoum’s theorem. (2+-6)

ba Wheat should be the length of simple pendulum whose time period ta one second? What is
_ frequency of seconds pendutum? (4*1)
_ QS 8 Define and explain absolute patential energy. Prove that sheolute PE, = a, . (2°6)
_ b. A wheel of a machine is rotating at a steady rate of 320 rev min™ . Find:

w@ its angular velocity

—~ i} The linear velocity of @ point on the wheel at 0.25 m from axle. (05)

i elec seems eesnennesn® serene ee \
G1 Choose the correct answer A/B/C /D by filling the relevant bubble for each question on the OMR

• Anewer Sheet according to the instructions given there. Each part carries one mark.
4) Which of the following is a pair of SI bese units?
~ A Ampere, Joule a Coulomb, Second
_ c Kilogram, Kelvin D. Newton, Meter
2 em ?
— Ga
A “a 8. jan c 10*m 0. 10%
x A person walks first 10 km north and 20 km east. Then the magnitude of resuftant vector is:
• A 20.36 km B. 22.36 kn c. 22.46 km o. 25.23 km
4) WS the scalar product 4B =0 , then which of the following is NOT correct?
[A
[4-0 [Taro [eo [eo
aoe [ao

## Subjective 1st year physics paper

_ 8} Acar takes 1 hour to travet 100 km along a main road and than ){ hour to travel 20 km along a aide road,
What és the average speed of the car for the Whole Journisy?
~ A 6Dkah* 8. 70kanh™* C. — 80kanh* 0. 100k
. 6) Rate of change of velocity is called: A Speed 8. Distance c. Acceteration D. Ossplacement 7 An example of non-conservative farce la:
A Electric force: a Magnetic farce
~ G. Gravitational force BD. Frictional force
8) The expression for escape velocity is given by:
A Agr? B faeR c. af D. -agR
9) Avtificial satelites move around:
— A Moon B. Sun G Stars DB. Eacth
10) ‘What ie the moment of inerta of a solid cylinder?
A MR B. iarr c Zar pda
41} The pressure will be low where the speed of the fluid is:
— A Zero 6. High G. Low oD. Constant
12) If the period of ceciilation of mass (M) suspended from a spring is 25. then period of maes 4M should be:
7 A 1s B. 26 c. 4s oO. 8s
13) tn an lectated system the total energy of a vibraling mass and spring is:
~ A Constant 8. Variable c. Low D. High
_ 44) There is no net transfer of energy by particles of medium in:
A Longitudinal wave B. Transverse wave
_ CG Progressive wave 0, Stationary wave
15) Which of the following factors has no effect on the epeed of sound in 3 gas?
_ A Humidity 6. Pressure CG Temperature O. Denaity
18) A real gas can be approximated to an ideal gas at
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