Faisalabad Board 2017
PHYSICS  Inter Part—1
Time Allowed: 3 Hours   Group 1     

          
Note:-Three are THREE sections in this paper i.e. Section A. B and C. Attempt Section-A on the same paper and return it to the superintendent within the given time. No marks will be awarded for Cutting, Erasing or Overwriting. Marks of Identification will lead to UFM case, Mobile Phone etc. are not allowed in the examination hall.
Q1. Write the correct option i.e. A, B, C or D in the empty, box provided opposite to each part.

• The dimension of l/g is same as that of:

1. Time
2. Energy
3. Velocity
4. Force

•  ABsinnxABsinnx

1. A²B²sin²θ
2. A²B²
3. A²B²n
4. O

• A paratrooper moves downward with:

1. Zero acceleration
2. Constant acceleration
3. Positive acceleration
4. Negative acceleration

• Velocity of an object dropped from a building at any instant‘e is given by:

1. 1/2gt²
2. Vit1/2gt²
3. at
4.  gt

• The power needed to lift a mass of 5000g to height of 1m in 2 second is:

1. 2.45 watt
2. 24.5 watt
3. 245 watt
4. 2.45 k watt

• The ratio of velocity of disc to velocity of hoop is:

1. 2/√3
2. 4/√3
3. 2/3
4. 4/3

• The angular velocity' of the minute hand of a clock is:

1. 2πrad s^-1
2. πrad s^-1
3. π/60rad s^-1
4. π/180 rad s^-1

• The expression fur the time period of low flying satellite put into the orbit is:

1. T=2πR/g
2. T=2πR/G
3. T=4πV/R
4. T=2πR/V

• A fog droplet falls vertically through air with an acceleration:

1. Equal to 'g'
2. Less than 'g'
3. Zero
4. Greater than “g”

• At which place the motion of a simple pendulum will be slowest:

1. Karachi
2. K-2
3. Murree
4. Lahore

• The periodic variations of sound between maximum and minimum loudness are called:

1. Doppler's effect
2. Reflection
3. Laplace correction
4. Beats

• The velocity of sound in vacuum is:

1. 332ms^-1
2. 280ms^-1
3. Zero
4. 333ms^-1

• The distance between 1st node and 4th antinode Is:

1. 7/4&lambda
2. 5λ/4
3. 5λ/4
4. 14λ/4

• In Young's double slit experiment, the position for bright fringe is:

1. Y_m=mλd/L
2. Y_m=m(mλ/Ld)
3. Y_m=m(mλl/d )
4. Y_m=m(mLD/λ)

• In Michelson's experiment, the angle subtended by a side of the eight sided mirror is:

1. π/8rad
2. π/4rad
3. π/2rad.
4. π/6rad

• Unit of thermodynamic scale of temperature is:

1. Centigrade
2. Fahrenheit
3. Kelvin
4. Celsius

• First law of thermodynamics for an adiabatic process is:

1. Q-ΔU
2. Q=W
3. W=Q+U
4. W=-ΔU 

SUBJECTIVE PART
SECTION B

Q2: Write short answers to any EIGHT (8) questions.

• Define radian and steradian.
• Is a zero significant or not? Explain.
• How can you assess the uncertainty in the average value of many measurements?
• Define light year. How many meters are them in one light year if speed of light is 3 x105kmss?
• Explain rectangular coordinate System.
• What is difference between moment arm and moment of force?
• Name the different conditions that make A×B=0.
• Find the angle of projection of a projectile for which its maximum height and horizontal range are equal.
• Define impulse and show that how it is related to linear momentum?
• Name the quantities which can be calculated from velocity-time graph and how these can be calculated?
• Define time of flight and range of a projectile.
• What is the difference between laminar and turbulent flow of fluid?

Q3. Write short answers to any EIGHT (8) questions.

• When a rocket re-enters the atmosphere its nose cone becomes very hot where this heat energy does come from?
• Differentiate between conservative and non-conservative forces. Give examples.
• Describe four uses of solar cells.
• When mud flies off the tyre of a moving bicycle, in which direction does it fly?
• How would you determine the direction of angular momentum? Give example.
• What is meant by moment of inertia? Explain its significance.
• Does the acceleration of a simple harmonic oscillator remain constant during its motion? Is the acceleration zero at any point? Explain briefly.
• Can we have an ideal simple pendulum? Explain briefly.
• Write one advantage and one disadvantage of resonance.
• How temperature and density of the medium affect the speed of sound?
• What is the difference between interference and beats?
• What changes are observed if a wave is reflected from a denser median"?

Q4: Write short answers to any SIX (6) questions.

• What do you mean by the term wave front and ray of Flight?
• Under what conditions two or more sources at light behave' as coherent sources?
• Can visible light produce interference fringes
• Write the pressure of light as transmission carrier wave over radio wave carrier.
• Why would it be advantageous to use blue light with a compound microscope?
• Why the pressure of a gas.in a car tyre does increases when it is driven through some distance?
• What do you mean by triple point of water?
• Write Kelvin statement of the second law of thermodynamics.
• Sketch the schematic diagram of refrigerator.

SECTION-C

Note: Attempt any THREE questions.

Q5.

1. State and explain the scalar product of two vectors. Write its four characteristics.
2. A ball is thrown horizontally from a height of 10m with velocity 21ms^-1. How far off it hit the ground and with what velocity?

Q6.

1. Define gravitational field. Prove that work done in the earth's gravitational field is independent of the path followed.
2. A gramophone record tum table accelerates from rest to an angular velocity of 45.0 rev min^-1 in 1.60s. What is its average angular acceleration?

Q7.

1. Define molar specific heat of a gas. Prove that C_p-C_v=R
2. How large must a heating duct be if air moving 3ms-1 along it can replenish the air in a room of 300m3 volume every 15 min? Assuming the air's density remains constant.

Q8.

1. Define simple pendulum. Derive the expression for its time period.
2. A stationary wave is established in a string which is 120cm long and fixed at both ends. The string vibrates in four segments, at a frequency of 120Hz. Determine its wavelength and fundamental frequency.

Q9.

1. Explain Young's double slits experiment. Derive the relation for position of mth bright and dark fringe from the center of the screen.
2. An astronomical telescope having magnifying power of 5 consists of two thin lenses 24cm apart. Find the focal lengths of the lenses.