MODEL QUESTION PAPER PHYSICS +1

SET 9

I. Match the following
A                                                     B
a) Newton’s third law                   PV= a constant
b)Bernoulli’s theorem                    F = ma
c) Isothermal change                    Stress α Strain
d) Hooke’s Law                          Recoil of gun
Venturimeter                               Law of conservation of energy (4 x ½ = 2)
II. The velocity of a particle moving in one dimension changes according to the relation
V = at3 – bt2where v is in m/s and t in seconds. (numerical value of a = 2 and b = 1)
a) Find the dimensions of a and b (2)
b) What is the velocity in the 3rd second (1)
III. A player throws a ball vertically upward with a speed 49 m/s
a) What is the direction of acceleration of the ball during the
i) upward and ii)downward motion. (1)
b) What is the velocity and acceleration of the ball at the highest point? (2)
c) Choosing the upward direction as the +ve direction of x-axis, give the signs of
position (x) and velocity (v) during the upward and downward motion of the ball.
Chose x=0 to be the location of the ball from where it was thrown and t=0 to be
the corresponding time. (g = 9.8m/s2) (1)
IV. Two forces of magnitude F each are acting at a point.
a) The magnitude of the sum of these two forces need not be 2F always – Justify (1)
b) For what angle between these two forces, the magnitude of the resultant
becomes F itself. (1)
V. An object that is in flight after being projected is called projectile.
a) At the highest point, what are the vertical and horizontal components of its velocity? (1)
b) In Javelin throw, 45o is preferred. Justify. (1)
c) Obtain the expression for the range of the projectile (2)
OR
A stone tied to a string is whirled in a horizontal circle with constant speed.
a) What is the direction acceleration of the stone? (1)
b) Draw the figure representing the direction of velocity of the stone at two different
instants, during its motion. (1)
c) Use the figure to obtain an expression for centripetal acceleration (2)
VI. Bernoulli’s theorem is basically about the conservation of energy of a non viscous fluid
in steady flow .
a) State and explain Bernoulli’s Principle (1)
b) Derive Bernoulli’s equation (2½)
c) A spin ball projected deviates from its original parabolic trajectory. Why ? (1)
VII. Free liquid drops and bubbles are spherical in shape if the effect of gravity can be
neglected.
a) How will you explain this? (1)
b) What is the excess pressure inside a drop of mercury of radius 3mm at room
temperature? The surface tension of mercury at room temperature is 4.65 x 10-1 N/m (2)
VIII. In rotational motion Moment of inertia plays a similar role as mass does in linear motion.
a) Give an expression for moment of inertia of a rigid body. (½)
b) State and explain perpendicular axes theorem. (2)
c) Moment of inertia of a ring about an axis passing through centre and
perpendicular to the plane of the ring is MR2. Find Moment of inertia about any of
its diameter. (1)
IX. A body of mass M and radius R is allowed to roll along an inclined surface of inclination θ
and height h.
a) Obtain the expression for velocity of the body when it reaches the bottom of the plane (2)
b) Obtain the acceleration of the body along the inclined plane (1)
c) If a solid cylinder and hollow cylinder of same mass and radius are allowed to fall
along the plane from same height, which will reach bottom first and why? (1)
X. Kepler’s laws of planetary motion explain the motion of planet around sun.
a) Obtain a relation between angular momentum and areal velocity of the planet (2)
b) State and prove kepler’s second law (2)
XI. a) Escape velocity from the surface of earth is 11.2km/s. A body is projected with a speed
twice the escape speed from earth. What is the speed of the object far away from earth
(infinity)? Ignore the presence of other planets and sun. (3)
XII. A gas taken in a cylinder with non-conducting walls and frictionless movable piston does
work when heat is supplied to it. Find the expressions for work done if the process is
a)Isothermal b) Adiabatic (4)
XIII. Heat engine is device which converts heat energy to mechanical energy.
a) Draw Carnot cycle and what are process involved in Carnot cycle (2)
b) “The efficiency of a heat engine can never be 100% and the coefficient
Performance of a refrigerator can never be infinity” – Which law of
thermodynamics, put this limitation? State and explain this law (2)
OR
In a thermodynamic process neither heat is absorbed nor rejected
a) Name the process (1)
b) Obtain the expression for work done during this process (3)
XIV. Any motion which repeats itself at regular intervals of time is called periodic motion.
a) What is the condition for a periodic motion to be Simple Harmonic? Give an
example for SHM (1½)
b) Write the expression for total energy of a particle which is in SHM. For what value
of displacement KE and PE are equal during the motion? (2)
XV. In sonometer experiment a segment of a stretched string is vibrated using a tuning fork.
a) Why for a particular length of the segment the paper rider on it vibrates
vigorously and then thrown off? Name the phenomenon (1½)
b) Obtain the expression for the frequency of fundamental mode of vibration of the
string. (2)
XVI. A person likes to stop and park his car on a steep place, which has an inclination of
150 with the horizontal.
a) What should be the minimum friction between the wheels and surface to prevent
the car from sliding down? (1)
b) Whether the safe parking in this place depends on the mass of the car? Give
reason. (2)
XVII. Jumping athletes usually made to land in loose sand. Why (1)
XVIII. Energy neither be created nor be destroyed but can only change from one form to
another.
a) Prove this in the case of a freely falling body (2)
b) A bus and a car are moving with same kinetic energy. Which has greater
Momentum? If same retarding force is applied to both, which one will come to
rest in a shorter time? Why? (2)