GUJRNAWALA BOARD 2013
PAPER PHYSICS
PART-I
Time: 20 Min.
(Objective Part)
Marks: 17
Note: You have four choice 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 circles. Cutting or filling two or more circles will result in zero mark in that question.

• Bending of light around the edges of an obstacle is known as:
  
  (a) Refraction
  (b) Polarization
  (c) Diffraction
  (d) Interference
  
  
• The distance between two consecutive nodes is :
  
  (a) 1
  (b) A
  (c) 2A
  (d) 4A
  
  
• Distance covered during one vibration of an oscillating body in te’’’’’’s of amplitude ' A' is:
  
  (a)
  (b) A
  (c) 2A
  (d) 4A
  
  
• S.I unit for angular displacement is :
  
  (a) Metre
  (b) Degree
  (c) Revolution
  (d) Radian
  
  
• Laws of motion are not valid in a system which is ?
  
  (a) Moving with uniform velocity
  (b) At rest
  (c) Isolated
  (d) Non-inertial
  
  
• Boltzman constant ' K' is given as :
  
  (a) RN_A
  (b) R/N_A
  (c) N_A/R
  (d) 1/RN_A
  
  
• The error in the value of speed of sound calculated by Newton at S. T. P. is about:
  
  (a) 14%
  (b) 15%
  (c) 16%
  (d) 20%
  
  
• If the pressure of the gas is doubled, then the speed of sound.
  
  (a) Is also doubled
  (b) Becomes half
  (c) Is not affected
  (d) Increases by four times
  
  
• The period of revolution of a geo-stationary satellite is equal to:
  
  (a) 1 hour
  (b) 84 min.approximately
  (c) 1 day
  (d) 1 month
  
  
• If the direction of force is perpendicular to the direction of motion of body , then work done is :
  
  (a) Minimum
  (b) Maximum
  (c) Zero
  (d) Infinity
  
  
• What is the angle of projection of a projectile for which its maximum height and horizontal range are equal ?
  
  (a) 46°
  (b) 56°
  (c) 66°
  (d) 76'
  
  
• The S.I unit of solid angle is:
  
  (a) Steradian
  (b) Degree
  (c) Revolution
  (d) Radian
  
  
• Which is not the example of adiabatic process?
  
  (a) Rapid escape of air from brust tyre
  (b) Rapid expansion of air
  (c) Conversion of water into ice in a refrigerator formation in the atmosphere
  (d) Cloud
  
  
• One torr is equal to :
  
  (a) 1.333N / m²
  (b) 133.3N / m²
  (c) 0.1333N / m²
  (d) 13.33N /m²
  
  
• The magnitudes of cross product and dot product of two vectors are equal. The angle between the vectors is:
  
  (a) Zero
  (b) 90°
  (c) 180°
  (d) 45°
  
  
• For normal adjustment , the length of astronomical telescope is:
  
  (a) f_o
  (b) f_of_o
  (c) f_o+f_o
  (d) f_o/f_o
  
  
• A satellite moving round the earth constitutes.
  
  (a) Intertial frame of reference
  (b) Non-intertial frame of reference
  (c) Neither intertial nor non-intertial
  (d) Both intertial and non-intertial

Time: 3:10 Hours
 (Subjective Part)
 Marks: 83
Section II

Question#2
Attempt any EIGHT short questions.                                           (8 x 2 = 16)

• Name serval repetitive phenomenon occurring in nature which could serve as reasonable time standards.
• Why do we find it useful to have two units for amount of substance, kilograme and mole'?
• Distinguish between base and derived units.
• How many nanoseconds in one year are there?
• Define the terms unit vector and position vector .
• Can you add zero to a null vector ?
• Give two conditions of equilibrium .
• Define impulse and give its relation with momentum
• Motion with constant velocity is a special case of motion with constant acceleration. Is this statement true?
• Can velocity of an object revere the direction when acceleration is constant? If so give an example.
• Explain how swing is produced in a fast moving cricket ball
• Explain circumstances in which acceleration a and velocity V of a car.
  (i) a is zero but v is not zero (ii) v is zero but a is not zero

Question#3
Attempt any EIGHT short questions.                         (8 x 2 = 16)

• A girl drops a cup from certain height which breaks into pieces. What energy changes are involved?
• A boy uses a catapult to throw a stone which accidentally smashes a green house window . List the possible energy changes.
• What is escape velocity and its mathematical expression?
• When a mud files off the tyre of a moving bicycle, in what direction does it fly?
• Why does a diver changes his body postion before and after diving in the pool?
• What are satellites and how they move around the earth?
• Name two characteristics of simple harmonic motion.
• Can we realize an ideal simple pendulum ?
• Define the term resonance.
• Differentiate between longitudinal waves and transverse waves.
• Why does sound travel faster in solids than in gases?
• How are beats useful in tuning the musical instruments?

Question#4
Attempt any SIX short questions. (6 x 2 = 12)

• Define wave front and spherical wave front.
• How would you manage to get more orders of spectra using a diffraction grating?
• Under what conditions two or more sources of light behave as coherent sources?
• One can buy a cheap microscope for use by the children. The images seen in such a microscope have couloured edges. Why is this so
• Why would it be advantageous to use blue light with a compound microscope?
• Derive Boyle's law from kinetic theory of gases.
• Define reversible process and irreversible process.
• Does entropy of a system increase or decrease due to friction ?
• Why does the perssure of a gas in a car tyre increase when it is driven through some distance'?

Attempt any THREE questions.                                        (8 x 3 = 24)

Question#5

(a) Define scalar product of two vectors and give its four characteristics.
(b) A football is thrown along an angle of 30° with respect to horizontal to throw 40 m pass. What must be the intial speed of the ball?

Question#6

(a) Describe work energy principle.
(b) A 1000 kg car travelling with a speed of 144 km h^-1 round a curve of radius 100 m. Find necessary centripetal force.

Question#7

(a) What is drawback of Newton's formula for speed of sound in air? How Laplace corrected it?
(b) A simple pendulum is 50.0 cm long. What will be its frequency of vibration at a place where 9.8m/ s²?

Question#8

(a) Describe the Michelson's experiment for calculation of speed of light.
(b) In a double slit experiment, the second order maximum occurs at  = 0 .25°. The wavekength is 650
       (i)Determine the slit separation.

Question#9

(a) Explain isothermal process and adiabatic process.
(b) What gauge pressure is required in the city mains for a stream from a fire house connected to the mains to reach a vertical height of 15.0 m?

Question#10(a)

• What is vernier constant?
• What do you know about zero error?
• Define weight and write its SI unit.                         
• What is second pendulum?
• What is the difference between a real image and a virtual image?
• Define critical angle.
  
  (b) Write down the brief procedure to show experimentally that time period of simple pendulum is independent of amplitude. OR Write down the brief procedure to find out the focal length of a convex lens experimentally.
  
  (c)
  
  
• What can you conclude from the graph?                             (4)
• Find the value of 'g from the graph.
  picture
  
  (i) What do you infer from the graph?
  (ii) Find our the focal length of a lens from the graph.
  picture