**Lahore Board 2012**

**Inter (Part I)**

**Inter (Part-I) Lahore Bo012**

**Physic (Compulsory)**

**Paper I (Objective Type)**

**Time Allowed: 20 Minutes**

**Max. Marks: 17**

**Group-I**

**Note:**You have four choices for each objective type question as A, B, C and D. The choice which you think is correct; fill that circle in front of that question number. Use marker or pen to fill the circle. Cutting or filling two or more circles will result in zero mark in that question. Attempt as many questions as given in objective type question paper and leave others blank.

1 SI unit of pressure is:

(A) N_m2

(B) N2_m

(C) N_m-2

(D) N-2_m

The sum of three number, 2.7543,4.10 and 1.273, up to correct decimal place is:

(A) 8.12

(B) 8.13

(C) 8.1273

(D) 8.127

The position vector of a point P (a,b,c) in YX-Plane is given by

(A) r=ai+bj

(B) r=ai+ck

(C) r=bj+ck

(D) r=ai+bj+ck

Mathematically unit vector is given by:

(A) A=AA

(B) AA/A

(C) A=A/A

( D) A= A.A

Water flows out from a pipe at 3kg /sec and its velocity changes from 5m/sec to zero on striking the well, the force due to water flow is:

(A) 3N

(B) 5N

(C) 10N

(D) 15N

Power can be defined as the product of:

(A) Force and displacement

(B) Force and time

(C) force and velocity

(D) Force and mass

The SI unit of angular acceleration is:

(A) Rad/sec2

(B) sec2

(C) rad/sec

(D) rev/sec

The apparent weight of a man in a lift moving down with an acceleration of 9.8m/s2 is:

(A) Zero

(B) 19.6

(C) 9.8 N

(D) infinity

The mathematical relation, v2 = is known as:

(A) Equation of community

(B) Amplitude of vibration

(C) Bernoulli’s equation

(D) Ventri relation

Time period simple pendulum only depends on:

(A) Mass of the bob

(B) Amplitude of vibration

(C) Length of the pendulum

(D) Size of the bob

10 waves pass through the medium in one sec. with a speed of 10 m/s, the wavelength of waves is:

(A) 1m

(B) 10m

(C) 20m

(D) 100m

Radar system is an application of:

(A) Interference

(B) Beats

(C) stationary waves

(D) Doppler effect

The effect path difference between two reflected beams in x-rays diffraction by crystals is:

(A) d sin á¶¿

(B) 2 d sin

(C) 2d sin á¶¿

(D) d sin (2á¶¿)

Longitudinal waves do not exhibit:

(A) Reflection

(B) Refraction

(C) Diffraction

(D) Polarization

In the newer systems of fibber optics, signals are regenerated by placing repeater, which may be separated by as much as:

(A) 30km

(B) 50km

(C) 100km

(D) 500km

The JK

(A) JK

(B)

(C)

(D)

Working cycle of a typical petrol engine consist of:

(A) Two strokes

(B) Four strokes

(C) six strokes

(D) Eight Strokes

Inter (Part-I) Lahore Board 2012

PHYSICS

PAPER: I (SUBJECTIVE TYPE)

Time: 2:40 Hours

Marks: 68

(Group – I)

SECTION - I

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

How many nano-seconds are there in 1 year?

Give the drawbacks to use the period of a pendulum as a time standard.

What are the dimensions and units of gravitational constant 'G' in the formula F=

What is negative of a vector? How a vector B is subtracted from a vector A?

Find the unit vector of the vector A = 4i + 3j.

Can a body rotate about its centre of gravity under the action of its weigth?

Differentiate between elastic and inelastic collision.

What is projectile motion? In what direction acceleration is zero-in this nation?

Define impulse- and show that how it is related to linear momentum.

Show that 1 kwh = 3.6 x 106 j.

An object has 1 j of potential energy. Explain what does it mean.

Define power. Write its SI unit.

3. Write short answers to any EIGHT (8) questions: (16)

What is meant by moment of inertia? Explain its significance.

Explain the difference between tangential velocity and angular velocity.

State the direction. the following vectors in simple situation:

(A) Angular momentum (B) Angular velocity

Explain, how the swing is produced in a fast-moving of carburetor of a motorcar

Considering Bernoulli's principle, explain the working of a carburetor of a motor car.

Write few lines on blood flow.

State Torricelli's theorem.

What happens to the period of a simple pendulum if its length is doubled?

In relation to SHM, explain the equation:

(A) y = A sin (Ï‰t+Ð¤) (B) a=-Ï‰2 x

What is the velocity of sound in air, if temperature of air is 20°C?

Is it possible for two identical waves traveling in the same direction along the string to give rise to a stationary wave?

Explain the term "Beats".

4. Write short answers to any SIX (6) questions:

How can the distance between interference fringes affect by the separation between the slits of Young's experiment? Can fringes disappear?

An oil film spreading over a wet footpath shows colors. Explain how does it happen.

How would you distinguish between un-polarized and plane-polarized lights?

One can buy a cheap microscope for use by the children. The images seen in ' such a microscope have colored edges. Why is this so?

How the power is lost in optical fiber through dispersion? Explain.

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?

Why Is the average velocity of the molecules in a gas zero but the average of the square of the velocities is not zero?

Specific heat of a gas at constant pressure is greater than specific heat at constant volume. Why?

Can the mechanical energy be converted completely into heat energy? If so, give an example.

SECTION - II

Note: Attempt any three questions.

5(A) . Define elastic collisions. Show that for elastic collisions in one dimension, the velocity of approach is equal to the velocity of separation

(B) Given that A=i-2j+3i-4k

6(A) Define conservative field. prove that the work done I the earth’s gravitational field of independent of the path followed.

(B) What should be the orbital speed of launch a satellite in a circular orbit 900 km above the surface of earth? (take mass of the earth as 6.0x1024 kg and its radius 6400km)

7.(A) Define molar specific heat and prove the relation cp-cv=R

(B) How large must a heating duct be if air moving with 3.0 ms-1 along it can replenish the air in a room of 300 m3 volume every 15 min? (Assume the air’s density remains constant)

8. (A) Define and explain simple pendulum.

(B) A stationaory wave is established in a string which is 120 cm long and fixed at both ends. The fundamental frequency.

9.(A) Describe how Michelson measured the speed of light

(B) in a double slit experiment, the second order maximum occurs at á¶¿=0.250. the wavelength is 650 mn, determine the slit separation

**Lahore Board 2012**

**Inter (Part I) Inter (Part-I) Lahore Bo012**

**Physic (Compulsory**

**Paper I (Objective Type)**

**Time Allowed: 20 MinutesMax.**

**Marks: 17**

**(Group-II)**

**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. Write the letter A,B,C or D in the Colum (Write correct option) against each question also .if there is a contradiction in the bubble and hand written answer, bubble option will be considered correct.

SI unit of intensity of light is:

(A) Candela

(B)

(C)

(D)

Femto means:

(A) 10-15

(B) 10-18

(C) 10-2

(D) 10-12

Self product of a vector A is equal to:

(A) A2

(B) Zero

(C) one

(D) Ã®.Ä´

Which pair of following forces give a resultant can be equal to zero :

(A) 2N

(B) 1 N and 4 N

(C) 2 N and 5 N

(D) I N and 2 N

Slope of velocity time graph represents :

(A) Average acceleration

(B) Average velocity

(C) Average speed

(D) Instantaneous acceleration

Which is the biggest unit of energy :

(A) Erg

(B) Joule

(C) Watt hour

(D) Kilowatt hour

Rotation kinetic energy od disc and hoop is

(A) Ià¹“2

(B) Ià¹“2

(C) 2Ià¹“2

(D) 3Ià¹“2

I radian :

(A) 57.30

(B) 54.30

(C) 2Ï€r

(D) 56.30

For which postion will the maximum blood pressure in the body have smallest value:

(A) Standing up right

(B) Sitting

(C) Lying horizontal

(D) Standing on ones head

Length of simple Pendulum whose time period is 1 sec :

(A) 0.25 m

(B) 25 m

(C) 100 m

(D) 0.25 cm

When a string vibrates in n loops with a frequency fn them wavelength is

(A) L

(B) L

(C) nl

(D) 2nl

One degree Celsius rise in temperature of air increases speed of sound by :

(A) 0.61 m/sec

(B) 6.1 m/sec

(C) 61 m/sec

(D) 6.1 cm/sec

Wavelength of x-rays is of the order of :

(A) 10-10 m

(B) 10-8 m

(C) 10-6 m

(D) 10-4 m

Oscillating charges produced :

(A) Mechanical wave

(B) Electromagnetic wave

(C) Matter waves

(D) Longitudinal waves

Magnifying power of astronomical telescope is :

(A)

(B)

(C)

(D)

Value of Boltzman constant is :

(A) 1.38x10-23 j/k

(B) 13.8x10-23 j/k

(C) 0 .138 j/k

(D) 138x10-23 j/k

Efficiency of Diesel Engine is :

(A) 35%

(B) 25% to 30%

(C) 40% to 50%

(D) 50% to 60%

Inter (Part-I) Lahore Board 2012

PHYSICS

PAPER: I (SUBJECTIVE TYPE)

Time: 2:40 Hours

I Marks: 68

(Group – II)

SECTION - I

Q.No.2. Write short answers to any EIGHT (8) questions: (16)

Name several repetitive phenomena occurring in nature which could serve as reasonable times standards.

Write the dimensions of : (i) Pressure (ii) Density

How many years in one second?

How a vector is determined when rectangular components are are given?

Under what circumstances would a vector have components that are equal in magnitude?.

Can you add zero to a null vector?

Find out velocity of a heavy body ehen it collides elastically with a light stationary body.

Explain the circumstances in which velocity Y and A of a car are :

(i) Parallel (ii) Anti-parallel

At what point or points in its path does a projectile have its minimum speed, its maximum speed?

An object has 1 J of potential energy.explain what does it mean?

A boy uses a catapult to throw a stone which accidentally smashes a green house window.list the possible energy changes.

Show that work done on the body equal the change in its kinetic energy.

Q.No.3. Write short answers to any EIGHT (8) questions: (16)

Explain what do you understand by term “viscosity”.

Why fog droplets appear to be suspending in a air?

Explain how the swing is produced in a fast moving cricket ball.

What the radian? Calculate the number of degree in one radian.

When mud flies of the tyre of moving bicycle, in what direction does it fly? Explain.

Explain the deference between tangential velocity and the angular velocity.

Does the frequency depend on the amplitude for harmonic oscillator?

Can we realize an ideal simple pendulum?

What does happen to period of simple pendulum of its length is doubled?

Explain why sound travels faster in warm air then in cold air?

How the velocity of a weve will change if “Tension” is made 16 times?

A wave is produced along a stretched string but some of its particles permanently show zero displacement what type of wave is it

Q.No.4. Write short answers to any SIX (6) questions

What a coherent light? What is a common method of producing two coherent light beams?

What is fringes spacing? On what factors it depends/

What are thin films? Why the center of Newton rings is dark?

A telescope is made of an objective of focal length 20 cm and an eye piece of 5.0 cm, both lenses find the angular magnification.

Differentiate between cladding and jacket in optical fibres.

What is angular magnification? Find the the angular magnification of simple microscope of focal length is f= 5 cm.

Is it possible to convert internal energy into mechanical energy? Wxplain with an example.

Why does the pressure of a gas in a car tyre increase when it is driven for some distance?

Define entropy. Write its SI unit.

(Sectoin – II)

Note: attempt any three questions.

5 (A) Determine rectangular components of a vector A, making an angle q, with the horizontal. also define rectangular components of a vector.

(B) A truck weighing 2500 kg and working with velocity of 21 m/s, collides with the stationary car weighing 1000 kg. The truck and the car move to gather after the impact. Calculate their common velocity.

6.(A) What is absolute potential energy? Show that absolute potential energy is U = .

(B) A 1000 kg car travelling with a sped of 144 km h-1 round a curve of radius 100 m. find the necessary centripetal force

7.(A) Define molar specific heat of a gas, at constant pressure and at constant volume. Also drive a relation between the two. 5

(B) A tiny water droplet of radius 0.010 cm descends through air from a high building. Calculate its terminal velocity. Given that n for air = 19x10-6 kgm-1s-1 and density of water p =1000 kg m-3

8.(A) What is a simple pendulum? Show that its motion. is simple harmonic motion. Also derive expression fot its time period.

(B) the frequency of the note emitted by a stretched string is 300 Hz. What will be frequency of this not when the length of the wire is reduced by one third without changing the tension?

9.(A) Expalin the construcation and magnification of a compound microscope with ray-diagram.

(B) A light is incident normally on a grating which has 25x102 lines per centimeter.Compute the wavelength of a spectral lines for which the deviation in a second order is 150