11 Physics QP in ENglish
11 Physics QP in ENglish
11 Physics QP in ENglish
SECTION A
Q 1. What is an isothermal process? What are the essential conditions for an isothermal
process to take place?
Q 2. Why and how Laplace corrected Newton’s formula for velocity of sound in gases?
OR
Discuss the effect of following factors on the speed of sound:
(a) Pressure (b) Density (c) Humidity (d) Temperature
SECTION B
Q 4. A structural steel rod has a radius of 10 mm and a length of 1 m. A 100 kN force F stretches
it along its length. Calculate (a) the stress, (b) elongation, and (c) strain on the rod.
Given that the Young’s modulus of the structural steel is 2.0 × 1011 N m–2.
Q 5. Derive the ascent formula for rise of liquid in capillary tube. What will happen, if the
length of the capillary tube is smaller than the height to which the liquid rises. Explain.
Q 6. Explain how a small spherical rigid body attains terminal velocity while falling through a
viscous liquid. Hence derive an expression for the terminal speed.
Pr
ess
ur2N/
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m (
e,
P
OR
Two samples of an ideal gas initially at the same temperature and pressure are allowed
to expand from a volume V to 2V, one isothermally and other adiabatically. In which
case, will
(a) the work done be more?
(b) the final pressure be more?
(c) the final temperature be more? Justify your answers.
Q 9. Explain why
(a) there is no atmosphere on moon.
(b) there is fall in temperature with altitude.
Q 10. Draw (a) displacement time graph of a particle executing SHM with phase angle f
equal to zero (b) velocity-time graph and
(c) acceleration-time graph of the particle.
Q 11. (a) On what factors does the energy of a simple harmonically vibrating particle depends?
b) A 2 kg particle undergoes SHM according to x = 1.5 sin (πt/4+ π/ 6), when x is in
metre and t in second. What is the total mechanical energy of the particle?
OR
Plot the corresponding reference circle for each of the following simple harmonic
motions. Indicate the initial (t = 0) position of the particle, the radius of the circle, and
the angular speed of the rotating particle. For simplicity, the sense of rotation may be
fixed to be anticlockwise in every case: (x is in cm and t is in s) (a) x =-2sin( 3t+ π/3)
(b) x =cos( π/ 6-t)
SECTION C
Q 12. (i-v) Transverse waves forms if the particles of the medium vibrate at right angle to the
direction of wave motion energy propagation, the wave is called transverse wave. These
are propagated as crests and troughs. Longitudinal waves forms if the particles of the
medium vibrate in the direction of wave motion, the wave is called longitudinal. These
are propagated as compressions and rarefactions and wave is also known as pressure or
compressional wave. Wave on spring or sound waves in air are examples of longitudinal
waves.
(i). In a transverse wave, the particles of the medium
(a) vibrate in a direction perpendicular to the direction of the propagation
(b) vibrate in a direction parallel to the direction of the propagation
(c) move in circle
(d) move in ellipse.