Physics
Lahore Board 2016
Inter Part-I
Group-I
Time:20 Min.
Objective Type
Marks=17

Note: Four Possible answers A, B, C and D to each question are the given. The choice which you think is correct, fill that circle in front of that question with marker or pen ink in the answer-book cutting or filling two or more circles will result in zero mark in that question.

• In the relation F=6πɳɼv Dimension of co-efficient of viscosity ɳ is :

(A) [ML^-1 T^-1]
(B) [MLT^-1]
(C) [ML^-2 T^-1]
(D) [MLT]

• If Ā = 2+ j = 2k then |A| is:

(A) Zero
(B) 3
(C) 5
(D) 9

• The trajectory of a projectile is:

(A) Circle
(B) Parobola
(C) Hyperbola
(D) Straight line

• SI unit of impulse is:

(A) Kg ms^-1
(B) N.m
(C) N.S
(D) Nm²

• Work done will be maximum when angle between F and d is:

(A) 180⁰
(B) 90⁰
(C) 60⁰
(D) 0⁰

• The S.I unit of angular displacement is :

(A) Metre
(B) Kilometre
(C) Radiam
(D) Centimetre

• The rate ot change of angular velocity is called:

(A) Angular velocity
(B) Angular acceleration
(C) 3 g
(D) Angular Speed

• The value of ,’g’ at the centre of the earth is :

(A) Infinite
(B) 2g
(C) 3g
(D) Zero

• The systolic Pressure of a normal health person is:

(A) 120 torr
(B) 125 torr
(C) 115 torr
(D) 130 torr

• The relation between time period and frequency is:

(A) f =2πT
(B) f = 
(C) f =
(D) fT = 1

• The velocity of sound in vacuum is:

(A) Zero
(B) 332m/s
(C) 280 m/s
(D) 330 m/s

• The velocity of sound is greatest in :

(A) Steel
(B) Air
(C) Iron
(D) Water

• The distance between two adjacent bright or dark fringes is:

(A) ∆y =  
(B) ∆y =  
(C) ∆y =
(D) ∆y = ldƛ

• Speed of sound in aluminum at 20⁰ C is:

(A) 3600 m/s
(B) 5100 m/s
(C) 10 cm
(D) 25 m

• The distance of near point from the eye is about:

(A) 25 cm
(B) dm
(C) 10 cm
(D) 25 m

• The value of Boltzmann’s constant is:

(A) 1.38x10-²³ j/k
(B) 1.38x 10⁺²³ j/k
(C) 1.38x10^-23 j/k
(D) 1.38x10^-23 j/k

• Triple point of water is:

(A) 273.16 ⁰f
(B) 273.16 ⁰C
(C) 273.16 k
(D) 373.16 k

Physics
Lahore Board 2016
Inter Part-I
Group - I
Time : 2.40 hrs
Essay Type
Marks = 68

Section – I

2. Write short answers to any Eight (8) questions: (16)

• Name several repetitive phenomena occurring in nature which could serve as reasonable time standards.
• The period of simple pendulum is measured by a stop watch. What type of error are possible in the time period?
• What are base units, name all of them?
• Write down the units and dimensions of G from the
  Equation F= GmM/r²
  
• Prove that commutative law holds good in addition of vectors.
• Define null vector and equal vectors.
• Can a body rotate about the centre of gravity under the action of its own weight? Explain briefly with diagram.
• Can the velocity of an object reserve the direction when the acceleration is constant? Explain with an example.
• Explain the circumstances in which the velocity v and acceleration of a car are parallel and perpendicular.
• How would you find, the momentum of an explosive force? Explain with one example.
•  A 1500 kg car has its velocity reduced from 20 ms ^-1 to 15 ms ^-1 in 3.0 seconds. How large was the average retarding force?
• Explain briefly, how the swing is produced in a fast moving cricket ball with figure.

3. Write short notes on any Eight (8) questions: (16)

• Explain briefly about residual heat of earth.
• In which case is more work done? When a 50 kg bag of books is lifted through 50 cm, or when a 50 kg crate is pushed through 2 m across the floor with a force of 50 N?
• A girl drops a cup from a certain height, which breaks into pieces. What energy changes are involved?
• Define centripetal force and write its formula.
• A disc and a hoop start moving down from the top of an inclined plane at the same time. Which one will be moving faster on reaching the bottom?
• When mud files off the tyr of a moving bicycle, in what direction does it fly? Explain.
• Define damped oscillations.
• Does the acceleration of a simple harmonic oscillator remain constant during the motion? Is the acceleration ever zero? Explain briefly.
• If a mass spring system is ruming vertically and set into oscillations, why does the motion eventually stop?
• What is the effect of density on speed of sound? Explain briefly.
• How should a sound source move with respect to an observe so that the frequency of its sound does not change?
• What features do longitudinal waves have in common with transverse waves?

4. Write short answer to any six (6) questions: (12)

• Could you obtain Newton’s rings with transmitted light?
  If yes, would the pattern be different from obtained with reflected light?
• How would you manage to get more orders of spectra using a diffraction gating?
• Why the polarized sunglasses are better than ordinary sunglasses?
• Write down the three major components on which a fiber communication system consists.
• Why would it be advantageous to use blue light with a compound microscope?
• Is it possible to convert internal energy into mechanical energy? Explain with an example.
• State first law of thermodynamic. Write down its mathematical form.
• Is it possible to construct a heat engine that will not expel heat into the atmosphere? Explain briefly.
• Define triple point of water, also write down its value.

Section-II
Note: Attempt any THREE questions.

4. (a) Define torque. Calculate torque due to force acting on a rigid body. (5)

(b) A 100 gm golf ball is moving to the right with a velocity of 20 ms^-1 . It makes a head on collision with an 8 kg steel ball, initially at rest. Compute velocities of the balls after collision. (3)

6. (a) What is meant by centripetal force? Derive relations for centripetal force and centripetal acceleration. (5)

(b) A brick of mass 2 kg is dropped from a rest position 5 m above the ground. What is the velocity at a height 3 m above the ground? (3)

7. (a)State and derive equation of continuity A₁ V₁ = A₂ V_{2 .} (5)

(b) A Carnot engine whose low temperature reservoir is at 7̊ Chas an efficiency of 50%. It is desired to increase the efficiency to 70%. By how many degrees the temperature of the source be increased? (3)

8. (a) What is simple pendulum? Show that simple pendulum performs simple harmonic motion. Also find time period of simple pendulum. (5)

(b) A train is approaching a station at 90 kmh^-1 , sounding a whistle of frequency 1000 Hz . What will be the apparent frequency of the whistle as heard by a listener sitting on the platform? (3)

9. (a) Describe the construction and working of compound microscope and derive an expression for magnifying power. (5)

(b) In a double slit experiment, the second order maximum occurs at 0 = 25̊. The wavelength is 650 nm. Determine the slit separation. (3)

Physics
Lahore Board 2016
Inter Part-I
Group-II
Time:20 Min.
Objective Type
Marks=17

Note: Four Possible answers A, B, C and D to each question are the given. The choice which you think is correct, fill that circle in front of that question with marker or pen ink in the answer-book cutting or filling two or more circles will result in zero mark in that question.

• If the radius of earth is doubled then the value of critical velocity becomes:

(A)[ML^-1 T^-1]
(B) [MLT^-1]
(C) [ML^- ]
(D) [MLT]

• In reversible process the entropy of system:

(A) Remains constant
(B) Decreases
(C) Increase
(D) Becomes zero

• Increase in velocity of sound in air for 1⁰c rise in temperature is:

(A) 0.61cms^-1
(B) 61cms^-1
(C) 0.61ms^-1
(D) 61ms^-1

• Both the Dot product and cross product of two vectors à and B is zero, when:

(A) A and B are parallel to each other
(B) A and B are antiparallel
(C) A and B are Perpendicular
(D) Either the vector is zero

• A Wheel of radius 2 m turns through an angle of 57.3⁰ it lays out a tangential Distance:

(A) 2m
(B) 4m
(C) 57.3m
(D) 114.6m

• The Wavelength of Waves Produced By microwave oven is:

(A) 0.12cm
(B) 1cm
(C) 6cm
(D) 12cm

• The S.I unit of angular displacement is:

(A) Meter
(B) Kilometer
(C) Radian
(D) Centimeter

• The value of Boltzmann constant is:

(A) 6.02x10²³jk^-1
(B) 1.38x10²³jk^-1
(C) 1.38x10^-23jk^-1
(D) 6.02x10^-23jk^-1

• Information carrying capacity of optical fiber is called:

(A) Capacity
(B) Bandwidth
(C) Immunity
(D) Ability

• A force of 10 n acts on a body of mass 1 kg for 5 sec. to a distance of 10 m. The rate of change of momentum is:

(A) 50 N
(B) 25 N
(C) 20 N
(D) 10 N

• In Michelson interferometer to switch the fringes from bright to dark, the mirror should be displaced by:

(A) ƛ/4
(B) ƛ/3
(C) ƛ/4
(D) ƛ

• Escape velocity of a body of mass 1000 kg is 11 kms^-1 if the mass of the body is doubled then its escape velocity will be:

(A) 5.5 kms^-1
(B) 11 kms^-1
(C) 22 kms^-1
(D) 44 kms^-1

• If the tension of a stretched string is made four times then the velocity of wave:

(A) Remains
(B) Is halved
(C) Becomes twice
(D) becomes 4 times

• Which one of the following is the correct record for the diameter of a wire when measured with a screw gauge of least count of 0.001 cm?

(A) 2.3 cm
(B) 2.31 cm
(C) 2.312 cm
(D) 2.3124cm

• Vanturimetre is used to measure:

(A) Speed of fluid
(B) Pressure of fluid
(C) Volume of fluid
(D) Mass of fluid

• When two Indexical waves superimposed, which can change:

(A) Wavelength
(B) Frequency
(C) Velocity
(D) Amplitude

• An orbital speed of a satellite can be determined by the equation:

(A)  
(B)
(C)                                              
(D)

Physics
Lahore Board 2016
Inter Part-I
Group - II
Time : 2.40 hrs
Essay Type
Marks = 68

Section – I

2. Write short answers to any Eight (8) questions: (16)

• Give the drawbacks to use the period of simple pendulum as a time standard.
• How many meters are there in one light year?
• Write the dimensions of :
  (a) Pressure , (b) Density.
• What is meant by precise and accurate measurements?
• Define unit vector .How we find it?
• Two vectors have unequal magnitudes. Can their sum be zero? Explain.
• Is it possible to add a vector quantity to a scalar quantity? Explain.
• Find the relation for force due to water flow.
• At what point or points in its path does a projectile have its minimum speed, its maximum speed?
• Can the velocity of an object reserve the direction when acceleration is constant? Explain.
• Define impulse and show that how it is related to linear momentum.
• Why fog droplets appears to be suspended in air?

3. Write short notes on any Eight (8) questions: (16)

• Define conservative field. Give its two examples.
• Calculate the work done in kilo-joules in lifting a mass of 10 kg (at steady velocity) through a vertical height of 10 m.
• An object has 1 J of potential energy. Explain what does it mean.
• State the direction of the following vectors in simple situation, angular momentum and angular velocity.
• Why does a diver change his body positions before and after diving in the pool?
• Define angular momentum and give its dimensions.
• State Hook’s law. Write it in mathematical form.
• A mass-spring system is hung vertically and set into oscillation, why does the motion eventually stop/
• Does the acceleration of a simple harmonic oscillator remain constant during its motion? Is the acceleration ever zero? Explain.
• How beats are useful in tuning musical instruments?
• Explain why sound travels faster in warm air than in cold air.
• Why does sound travel faster in solids than in gases?

4. Write short answer to any six (6) questions: (12)

• An oil film spreading over a wet footpath shows colours. Explain how does it happen.
• Why the Polaroid sunglasses are better than ordinary sunglasses?
• What is Huygen’s principle?
• How the light is transmitted through optical fiber?
• What is the condition for total internal reflection?
• Specific heat of gas at constant pressure is greater than specific heat at constant volume. Why?
• Does entropy of a system increase or decrease due to friction?
• Write any two postulate of kinetic theory of gasses.
• Write any two examples of adiabatic process.

Section-II
Note: Attempt any THREE questions.

5.(a) Explain cross product of two vectors. State right hand rule and give at least four characteristics. (5)

(b) A truck weighing 2500 kg and moving with a velocity of 21 ms^-1 collides with a stationary car weighing 1000 kg. The truck and the car moves together after the impact. Calculate their common velocity. (3)

6.(a) What are geostationary satellites? Derive the relation for radius of Geostationary orbit. (5)

(b) A force of 400 N is required to overcome road friction and air resistance in propelling an auto mobile at 80 kmh^-1 . What power (kw) must the engine develop? (3)

7.(a) State and derive Bernoulli’s equation for an ideal fluid. (5)

(b) A heat engine performs 100 J of work and at the same time rejects 400 J of heat energy to cold reservoirs. What is the efficiency of the engine? (3)

8.(a) Define simple harmonic motion. Prove that energy is conserved for a body executing simple harmonic motion. (5)

(b) A church organ consists of pipes, each open at one end of different lengths. The minimum length is 30 mm and the largest is 4m. Calculate the frequency range of fundamental notes.(Speed of sound = 340 ms^-1) (3)

9.(a) Define molar specific heat of a gas at constant volume and pressure. Also prove C_p – C_v = R. (5)

(b) Certain globular protein particle has a density of 1246 kgm^-3. It falls through Pure water (n = 8.0 x 10^-4 Nms^-2) with a terminal speed of 3.0 cmh^-1. Find radius of particle. (3)