Bahawalpur board 2017
PHYSICS
Inter Part—1 Time Allowed: 3 Hours          
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.

• A Carrot Engine has an efficiency of 50%, when its ink temperature is at The Temperature of the source is:
  
  
  1. 273°
  2. 300°
  3. 327°
  4. 373°
  
  
• Which one of the following cannot be polarized:
  
  
  1. Ultra Violet Rays
  2. Radio Waves
  3. V Waves
  4. Sound waves
  
  
• Crests and Troughs are formed in:
  
  1. Longitudinal Waves
  2. Transverse Waves
  3. Stationary
  4. Compressional Waves
  
  
• If Length of the Pendulum is constant and its mass of the bob is doubled, its time period:
  
  
  1. Becomes Half
  2. Becomes One Third
  3. Becomes Doubled
  4. Remains Constant
  
  
• S.I. Unit of Impulse is:
  
  1. N.s
  2. N.m
  3. Ns^-1
  4. N.M^-1
  
  
  
• ^ Radian=____:
  
  
  1. 7°
  2. 3°
  3. 180°
  4. 7°
  
  
• A typical rocket consumes fuel about:
  
  
  1. 10000 Kg/s
  2. 15000 Kg/s
  3. 8000 Kg/s
  4. 660 Kg/s
  
  
• 1 Peta =
  
  
  1. 109
  2. 1012
  3. 1015
  4. 1018
  
  
• î(kˆ×î)= ___:
  
  
  1. 1
  2. 0
  3. î
  4. kˆ
  
  
• Which is not Conservative Force:
  
  
  1. "Electric Force
  2. Elastic Spring Force
  3. Gravitational Force
  4. Frictional Force
  
  
• The Ratio of maximum Orbital Velocity and Escape Velocity is:
  
  
  1. 4:1
  2. √2:1
  3. 2:1
  4. 1:√2
  
  
• The Dimensions of Angular Momentum L are:
  
  
  1. ML²T^-1
  2. MLT^-1
  3. ML²T^-1
  4. ML^-2T
  
  
•  Torr =____:
  
  
  1. 1.333Nm^-2
  2. 13.33Nm^-2
  3. 133.3Nm^-2
  4. 1333Nm^-2
  
  
• Longitudinal Waves 0of Frequencies less than 20Hz are known as:
  
  
  1. Infra Sound
  2. Ultra Sound
  3. Super Sonics
  4. Audible Sound
  
  
• Error in calculation of Newton's Formula for speed of sound is about:
  
  
  1. 6%
  2. 10%
  3. 16%
  4. 26%
  
  
• Fringes spacing in Young' Double Slit Experiment increases due to increase in:
  
  
  1. Slit Separation
  2. Wave-Length
  3. Order of Fringe
  4. Frequency of Source
  
  
• At constant temperature, If pressure of a given mass of a gas is halved, then its volume becomes:
  
  
  1. Halved
  2. Doubled
  3. Four Times
  4. Constant
  
  

SUBJECTIVE PART
SECTION B

Q3:Write short answers to any EIGHT (8) questions.
1. What is meant by Sonar? Explain.
2. Derive the define power in terms of velocity
3. Explain weightlessness in satellite.
4. What is meant by phase Angie and Initial phase?
5. Name at least two renewable and two non- renewable energy sources.
6. A boy uses a catapult to throw a stone which accidentally smashes a Green House window. List the possible energy changes.
7. What is the difference between angular acceleration and centripetal acceleration?
8. How many minimum number of communication are required for global coverage of T.V transmission and what is their height the surface of earth?
9. Can we realize an ideal simple pendulum? Explain.
10. Discuss the heating in Microwave Oven by Resonance.
11. Differentiate between traveling waves and stationary waves.
12. Why does sound travel faster in Solids than Gases?

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

1. What is the Contribution of Michelson to measure the-length of Standard Meter using interferometer?
2. Could you obtain Newton's Rings with transmitted light? If yes, would the pattern be different from obtained with reflected light?
3. On what factors, the distance between adjacent bright fringes in Young's Double Slits Experiment depend?
4. How the Power is our in Optical Fine?
5. If a person was looking through a telescope at the full moan, how would the appearance of the moon be changed by covering half of the objective lens?
6. What will be heat lost if internal energy decreases by and work of 120 J is done by the system?
7. Specific heat ofa gas at constant pressure is greater than specific heat at constant volume.
8. Explain why?
9. Is it possible to construct a heat engine that will not expel heat into the atmosphere?
10. Why Absolute Value of Internal Energy cannot be measured?
11. What is the Contribution of Michelson to measure the length of Standard Meter using Interferometer?
12. Could you obtain Newton's Rings with transmitted light? If yes, would the pattern be different from that obtained with reflected light?

Note: Attempt any THREE questions.

Q5:

1. Define vector Product of two Vectors Give its two examples and write four characteristics
2. An electron (m=9.1 0 10^-31 Kg) travelling at 2.0 x 107ms^-1 undergoes a head on Collision with a hydrogen Atom (m = 1.67x10^-27 kg) which is initially at rest. As summited Collision to be perfectly elastic and a motion to be along a straight line, find the velocity of Hydrogen Atom

Q6:

1. Define Absolute Potential Energy. Derive its Mathematical Expression.
2. The Earth rotates on its axis once a day, suppose by some process the Earth contracts that its Radius is only half as large as at present. How fast it will be rotating then?
   [For Sphere=2/5MR²]

Q7:

1. Describe the construction and working of CARNOT Engine: Also find its efficiency.
   
2. Water Flows through a hose whose internal d meter in I cm at a speed of ms^-1 What should be the diameter o the nozzle if the water is to emerge at 21 ms^-1?

Q8:

1. A Particle moving along a circle then as projection on the diameter of the circle executing S.H.M. Derive the ration for Velocity and Acceleration of SHM
2. An organ pipe has a length of 50 cm. find the frequency of its fundamental note and the next the next harmonic when it is open at both ends. (Speed of sound =350ms^-1

Q9:

1. What is a Telescope Draw its Ray - Diagram and derive a relation for its magnification power
2. Calculate the Wavelength of Light which illuminates two slits 0.5 nun apart and produces a pattern on a screen placed 200 cm away from the slits. The lust Bright Fringe ' observed at a distance of 2 4 mm from the Central Fringe.