BISE Sargodha · Class 11 · Physics

BISE Sargodha · Class 11 · Physics · 2025 · Group 2 · Subjective

2025

Source total marks: 68 Time allowed: 2.40 hours

Transcribed from the identified examination paper. Check the board, session and course before use. SchoolOrbit is not affiliated with the issuing board.

Transcription note

Board and 2025 attribution comes from an exact contemporary SRC world reproduction titled Sargodha 2025 Group 2, uploaded 21 May 2025. The supplied paper does not print a four-digit examination year or the full board name.

The annual examination session and old/new course are not printed and remain unspecified. The cohort range and production identifiers are retained as source text, not decoded into an examination sitting.

The recovered reverse continues after Q4(vii). Original wording, including “sounds”, “Viscuss” and “Drive”, is retained. No answer key or corrected scientific solution is supplied.

Individual long-part marks are not printed and remain unknown. The section expression 8 × 3 = 24 applies to three whole questions, not a guessed split between parts (a) and (b).

1125

Warning:- Please, do not write anything on this question paper except your Roll No.

Physics (Subjective)
Group 2nd
(Session 2021-23 to 2024-26)
Paper (I)
(Inter Part - I)

Section I

2.
Answer briefly any Eight parts from the followings:-
8 × 2 = 16
(i)
Given that $I = 0.84 \pm 0.05 A$ . Calculate Percentage uncertainty.
(ii)
What are two principal characteristics of an ideal standard?
(iii)
Give drawbacks to use the period of pendulum as the time standard.
(iv)
What are the dimensions of pressure and density?
(v)
Is it possible to add force into mass?
(vi)
The vector sum of three vectors gives a zero resultant. What can be the orientation of the vectors?
(vii)
Show that $\vec{A} \times \vec{B} \neq \vec{B} \times \vec{A}$ by diagram
(viii)
At what point or points does a projectile have its minimum & maximum speed? Explain.
(ix)
For which angle of projection, The range of projectile is half of its maximum range?
(x)
What is Law of Conservation of Linear momentum? Give example.
(xi)
A child starts from rest at the top of a slide $4 m$ high. What is its speed at the bottom of slide if it is frictionless?
(xii)
A boy uses a catapult to throw a stone which accidently smashes a green house window. List the possible energy changes.
3.
Answer briefly any Eight parts from the followings:-
8 × 2 = 16
(i)
Explain with example, how angular velocity of a body decreases with increase of radius of a circle and vice versa. Use $\vec{V} = r ω$ to support your answer.
(ii)
How would you describe the dependence of moment of inertia with mass distribution and orientation of the body?
(iii)
Why does a diver change his body position before and after diving in the pool?
(iv)
When mud flies off the tyre of a moving bicycle, in what direction does it fly?
(v)
Analyse analytically the three different pressures used in Bernoulli's equation
(vi)
Two row boats moving parallel in the same direction are pulled towards each other. Explain
(vii)
How would you analyse analytically the equation of simple pendulum $T = 2 π \sqrt{\frac{l}{g}}$
(viii)
What is resonance? Give one example.
(ix)
Does the acceleration of a simple harmonic oscillator remain constant during its motion? Is the acceleration ever zero? Explain
(x)
How would you explain longitudinal periodic waves. Use diagram to support your answer.
(xi)
What is the drawback in Newton's formula for speed of sound and how it is corrected by Laplace.
(xii)
As a result of distant explosion, an observer senses a ground tremor and then hears the explosion. Explain the time difference.
4.
Answer briefly any Six parts from the followings:-
6 × 2 = 12
(i)
Under what conditions two or more sources of light behave as coherent sources?
(ii)
An oil film spreading over a wet footpath shows colours. Explain how does it happen?
(iii)
What is wavefront? Define ray of light.
(iv)
What do you understand by linear magnification and angular magnification? Explain how a convex lens is used as a magnifier.
(v)
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?
(vi)
How is an astronomical telescope adjusted normally?
(vii)
Specific heat of a gas at constant pressure is greater than specific heat at constant volume. Why?
P.T.O
1130 -- 1125 SGD -- 17000
-- (02) --
(viii)
Is it possible to construct a heat engine that will not expel heat into the atmosphere?
(ix)
If pressure of a gas is $P$ and change in volume is $Δ V$ then show that work , $W = P Δ V$

Section II

Note: Attempt any three questions.

8 × 3 = 24

5.
(a)
Define isolated system and state law of conservation of linear momentum. Prove law of conservation of linear momentum for an isolated system of two masses.
(b)
A load of $10 N$ is suspended from a clothes line. This distorts the line so that it makes an angle of $15^{\circ}$ with the horizontal at each end. Find the tension in the clothes line.
6.
(a)
Define escape velocity. Derive a relation for escape velocity of an object on the surface of earth.
(b)
A $1000 k g$ car is travelling with a speed of $144 {k m h}^{- 1}$ sounds a curve of radius $100 m$ . Find the necessary centripetal force.
7.
(a)
What is Terminal Velocity? Show that Terminal Velocity is directly proportional to the Square of the radius of spherical body falling in a Viscuss medium
(b)
Find the average speed of oxygen molecules in air at S.T.P
8.
(a)
Drive an expression of Laplace's correction for speed of sound in air.
(b)
A simple pendulum is $50.0 c m$ long. What will be its frequency?
9.
(a)
How did Michelson determine the speed of light Experimentally. Explain it
(b)
An Astronomical Telescope having magnifying power of $5$ consist of two Thin lenses $24 c m$ apart. Find the focal length of lenses?
1130 -- 1125 SGD -- 17000