RAWALPINDI BOARD 2015
PAPER Physics PART-I
(Objective Part)
Time: 20 Minutes       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

• One Peta is equal to:

A) 10¹⁵
B)
C)
D)

• The cross product, is equal to

A) -i^
B)
C)
D)

• The slope of velocity-time graph at any instant represents:-

A) Instantaneous acceleration
B)
C)
D)

• The horizontal range of a projectile is maximum, when it is projected at an angle of

A) 45°
B)
C)
D)

• The ratio of dimensions of K.E and power is:

A) 1 : |T¹|
B)
C)
D)

• π radian is equal to:

A) 180°
B)
C)
D)

• The minimum number of correctly positioned communication satellites to cover whole populated earth is

A) 3
B)
C)
D)

• Speed of a hoop at the bottom of an inclined plane is

A)√gh
B)
C)
D)

• Which material has maximum

A) Glycerin
B)
C)
D)

• The expression for frequency of a mass  attached to a spring of spring Constant  

A)
B)
C)
D)

• The distance between two consecutive nodes or antinodes is

A) λ/2
B)
C)
D) .

• If the organ pipe is closed at one end, the frequency of fundamental harmonic is.

A) ƒ₁ = v/41
B)
C)
D)

• Increase in speed of sound for rise in temperature is

A) 61m/s
B)
C)
D)

• The centre of Newton’s rings is dark due to.

A) Destructive interference
B)
C)
D)

• The magnifying power of simple microscope is.

A) 1 + d/f
B)
C)
D)

• Which one is true for isothermal process?

A) g = w|ΔU = 0
B)
C)
D)

• Average translational kinetic energy of gas molecule is.

A) (3/2) KT
B)
C)
D)

Inter (Part-I) Rawalpindi Board 2015
Physics
Part I (Subjective)
Time Allowed: 3.10 Hours 
Max. Marks: 83

SECTION-I

2. Attempt any EIGHT short questions.

• Write the dimensions of i) Pressure ii) Density
• Why a motor cycle’s safety helmet is padded?
• If what can you say about the components of the two vectors ?
• Can you add zero to null vectors?
•  Explain the circumstances in which velocity “v” and acceleration “a” of a car are:
  Antiparallel
  Perpendicular to each other
• Show that range of a projectile is maximum when projectile is thrown at the angle of 45° with horizontal.
• An old saying is that “A chain is only as strong as its weakness link” what analogous statement can you make regarding experiment data used in computation?
• Two vectors have unequal magnitude. Can their sum be zero? Explain
• The period of simple pendulum is measured by a stop watch. What type of errors is possible in the time period?
• Motion with constant velocity is a special case of motion with constant acceleration. Is this statement true? Discuss.
• Give the drawbacks to use the period of simple pendulum as a time standard.
•  Two row boats moving parallel in the same direction are pulled towards each other. Explain.

3. Attempt any EIGHT short questions.

• Can we realize an ideal simple pendulum?
•  Define Node and Antinode.
•  Define power. Write its formula.
•  What are artificial satellites?
•  Define moment of inertia & write its formula.
• Name two characteristics of simple harmonic motion.
•  What is the difference between tangential velocity and angular velocity?
•  Does frequency depend upon amplitude for harmonic oscillator?   
• What sort of energy is in the following:
  Compressed springs
  A moving car
• What features do longitudinal waves have in common with transverse waves?
• Is it possible for two identical waves traveling in the same direction along a string to give rise to stationary waves?
•  A girl drops a cup from a certain height, which breaks into pieces. What energy changes are involved?

4. Attempt any SIX short questions.

• Specific heat of a gas at constant pressure is greater than specific heat at constant volume .Why?
• How would you manage to get more orders of spectra using a diffraction grating?
• Why does pressure of a gas in a car tyre increase when it is driven through some distance?
• Why would it be advantages to use blue light with a compound microscope?
• If a person was looking through a telescope at the full moon, how would the appearance of the moon be changed by convering half of the objective lens.
• Can visible light produce interference fringes? Explain
• Prove that Δy=λL/d
• Does entropy of a system increase or decrease due to friction?
• Prove that W=PΔV

SECTION-II

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

Question #5 
a) Derive expressions for the magnitude and direction of the resultant of two vectors, added by rectangular component method.
b) Find the angle of projection for which its maximum height and horizontal range are equal.

Question #6 
a) Define rotational K:E also derive formula for rotational K:E of a disc and a hope coming down an inclined plane.
b) How large a force is required to accelerate an electron (m=9.1×10³¹ kg) from rest to a speed of 2.0×10⁷ ms¹ through a distance of 5.0cm?

Question #7 
a) Explain interference. Find the conditions for
Constructive interference
Destructive interference
b) A simple pendulum is 25cm long. What will be its frequency of vibration at a place where  g = 9.8 ms^-2

Question #8
a)  Define simple microscope. Derive the expression for its magnifying power.
b)  Sodium light of wavelength 589nm is incident normally on a grating having 3000 lines per centimetre. What is the highest order of spectrum obtained with the grating?

Question #9
a) Derive Terricellis theorem and Venturi relation by applying Bernoulli's equation.
b) What is the average translational Kinetic energy of molecules in a gas at temperature 27°C

SECTION –III:

Question #10a
Answer any FOUR parts.

•  What are the main parts of vernier caliper?
•  What is the law of parallelogram?
•  Why the amplitude of simple pendulum is kept small?
•  What is meant by elastic limit?
•  What types of waves are set up on a vibrating string?
•  What is resonance?
• What is critical angle?
• What is magnifying glass?

Question #10b
Write down the brief procedure to show experimentally that the time period of simple pendulum is independent of mass of bob.

OR

Write brief procedure to find the speed of sound using resonance tube apparatus by end correction methods

Question #10c

Answer the following question on this basis of graph drawn:

1. What can you conclude from this graph?
2. Find the value of  from the graph.

  OR

Answer the following question on the basis of graph drawn:

1. Find the slope of the graph
2. Find the focal length from the graph