BISE Sargodha · Class 11 · Physics

BISE Sargodha · Class 11 · Physics · 2025 · Group 1 · 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 1, 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 source prints Q3(iv) twice. Both distinct questions are retained in their original positions. Original wording is preserved; 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 (I)
(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)
Give the drawbacks to use the period of pendulum as a time standard.
(ii)
Does Dimensional analysis give any information on constant of proportionality that may appear in algebraic expression? Explain.
(iii)
What is meant by Precision and accuracy
(iv)
(a) How many meters are there in one light year? (b) How many years in one second?
(v)
Can a vector have a component greater than vector's magnitude?
(vi)
Two vectors have unequal magnitudes: Can their sum be zero? explain.
(vii)
What is unit vector? Find the unit vector in the direction of vector $\vec{A} = 4 \hat{i} + 3 \hat{j}$
(viii)
Show that Impulse is equal to change in Momentum.
(ix)
At what point or points in its path does a projectile have its minimum speed, its maximum speed?
(x)
Motion with constant velocity is a special case of Motion with constant acceleration. Is this statement true? Discuss.
(xi)
Show that Power is a dot product of Force and Velocity
(xii)
A girl drops a cup from a certain height. which break into Pieces. What energy changes are involved?
3.
Answer briefly any Eight parts from the followings:-
8 × 2 = 16
(i)
Differentiate between real weight and apparent weight.
(ii)
What is meant by moment of inertia? Explain its significance.
(iii)
Show that orbital angular momentum $L_{o} = m v r$
(iv)
Prove that $1 r a d = {57.3}^{\circ}$
(v)
Write down conditions of an ideal fluid.
(iv)
Why fog droplets appear to be suspended in air?
(vii)
How the resonance plays an important role in working of microwave oven?
(viii)
Name two characteristics of simple harmonic motion.
(ix)
What is meant by Phase angle? Does it define angle between maximum displacement and the driving force?
(x)
What is effect of pressure and temperature on the speed of sound in a gas?
(xi)
Why does sound travel faster in solids than in gases?
(xii)
What features do longitudinal waves have in common with transverse waves ?
4.
Answer briefly any Six parts from the followings:-
6 × 2 = 12
(i)
Can the mechanical energy be completely converted into heat energy? If so give an example.
(ii)
What happens to the temperature of room, when an air conditioner is left running on a Table in the middle of room?
(iii)
State Carnot' Theorem and extended Carnot Theorem.
(iv)
What is the use of LED and microphone in signal transmission in optical fibre case
(v)
What is least distance of distinct vision
(vi)
How the power is lost in optical fibre through dispersion? Explain
(vii)
Can visible light produce interference fringes?
(viii)
Define wavefront and Ray of Light.
(ix)
How would you manage to get more orders of Spectra using a grating?

Section II

Note: Attempt any three questions.

8 × 3 = 24

5.
(a)
How would you define projectile motion and explain its motion on the basis of vertical component of velocity and height of the projectile, and find the velocity of landed projectile.
(b)
A spherical ball of weight $50 N$ is to be lifted over the step as shown in the fig. Calculate the minimum force needed just to lift it above the floor.
6.
(a)
What is the centripetal force? Derive relation for acceleration of a body moving under the influence of centripetal force
(b)
A force (thrust) of $400 N$ is required to overcome road friction and air resistance in propelling an automobile at $80 k m h^{- 1}$ . What power (kW) must the engine develop?
7.
(a)
Draw and explain Carnot Cycle. Using Carnot Cycle, find efficiency of Carnot engine
(b)
How large must a heating duct be if air moving at $3.0 m s^{- 1}$ along it can replenish the air in a room of $300 m^{3}$ volume every $15$ minutes? Assume the air's density remains constant.
8.
(a)
Prove that the total energy for a body executing simple harmonic motion remains constant.
(b)
Find the temperature at which the velocity of sound in air is two times its velocity at $10^{\circ} C$ .
9.
(a)
Explain Young's Double slite experiment for interference phenomenon. Derive Equations for maxima, minima and linear distance on the screen between adjacent bright fringes.
(b)
An astronomical telescope having magnifying power of ' $5$ ' consists of two thin lenses $24 c m$ apart. Find the focal lengths of lenses.
1128 - 1125SGD -- 17000