HSC Physics- 1st
Paper (Theo) Model Question for Class- XII
1. a. Explain
the scalar and vector products of two vectors, with necessary diagram. 5
b. Show
that the trajectory of a projectile is parabolic. 6
c. A
bullet after penetrating 3cm of a wall loses half of its speed. How far will
the bullet penetrate the wall afterwards? 4
Or,
- State Newton’s third law of motion. Prove the principle of conservation of momentum from this law. 5
- Prove that a
=
6
- A force of magnitude 30N acts on a body at rest and of mass 6kg. After 10s what will be its kinetic energy. 4
2. a. What
is called mean free path? Derive an expression for mean free path. 5
b. Prove
that Cp – Cv = R. 6
c. A
fixed amount of gas at 270 C is suddenly expanded to double its
original volume. What is the final temperature? (
g
= 1.4 ) 4
Or,
a . State and explain Stefan’s law and from this
law describe how Newton’s
law of cooling can be derived? 5
b. Describe
a method for determining latent heat of fusion of ice. 6
c. 5
Kg of ice at -100 C is mixed with 20 g of water at 400 C. What will be the final
temperature of the
mixture? 4
3. a. Distinguish between transverse and longitudinal
wave. 5
b. Derive
the general equation of a progressive wave. 6
c. The
frequency of a stationary wave in a medium is 320 Hz. The distance between two
successive
nodes of the
wave is 0.52m. Find the speed of the wave. 4
Or,
- What is called resonance, free and forced vibration? 2 + 1.5 +1.5 = 5
- State and explain the laws of transverse vibration of a stretched string. 6
- The string of a sonometer is in resonance with a tuning fork of frequency 200 Hz. If the length
of the string is
increased by 1%, How many beats will be heard? 4
4. Prove the principle of conservation of mechanical energy in
case of a simple pendulum. 5
Or,
Describe
Cavendish method to determine ‘G’.
5. Determine the differential equation of a simple harmonic
motion and find its general solution. 5
Or,
Define elastic potential energy.
Show that the elastic potential energy per unit volume of a
body =
5

6. Describe the experiment to determine the surface tension of
water by capillary rise method. 5
Or,
What is angle of contact? A large
drop is formed by 25 small drops of water, each of diameters
0.17×10-2
m. Find the energy
released. (Surface tension of water = 72 ×
10-3 Nm-1.)
7. What is called ideal black body? A
metallic sphere of radius 0.3 m radiates 25 W powers. Find the temperature of
the sphere. ( σ = 5.67 ×10-8 Wm-2
K-4 ) 5
Or,
State and explain Second law of
thermodynamics. Prove that η
=
. 2+3
= 5

8. Describe the construction and working principle of a
thermoelectric thermometer. 5
Or,
State with figure Wien’s law.
Explain Green house effect. 5
9. State and explain Newton’s law for the velocity of sound. Why
and how Laplace made correction
of Newton’s law? 5
Or,
Derive an expression for the
apparent frequency of sound when a source is moving towards the stationary
observer. 5
-0-
No comments:
Post a Comment