KENDRIYA VIDYALAYA NO.3 NAL BIKANER
HOLIDAY HOME WORK(WINTER BREAK)-2013-14
CLASS-XI(SCIENCE)
SUB: PHYSICS
Q.1 The Sun.s angular diameter is measured to be 1920. The distance D of
the Sun from the Earth is 1.496 1011 m.What is the diameter of the Sun ?
Q.2 We measure the period of oscillation of a simple pendulum. In successive measurements,
the readings turn out to be 2.63 s, 2.56 s, 2.42 s, 2.71s and 2.80 s. Calculate the absolute
errors,relative error or percentage error.
Q.3 The resistance R = V/I where V = (100 ± 5)V and I = (10 ± 0.2)A. Find the
percentage error in R.
Q4 Let us consider an equation
1/2m v m g h
where m is the mass of the body, v itsvelocity, g is the acceleration due to
gravity and h is the height. Check whether this equation is dimensionally correct.
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Q5 State the number of significant figures in the following :
(a) 0.007 m2
(b) 2.64 10 kg
(c) 0.2370 g cm.
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Q.6 A physical quantity P is related to four observables a, b, c and d as follows :
P= a 3b2/ c d
The percentage errors of measurement in a, b, c and d are 1%, 3%, 4% and 2%,
respectively. What is the percentage error in the quantity P ? If the value of P calculated
using the above relation turns out to be 3.763, to what value should you round off the result.
Q.7 The position of an object moving along x-axis is given by x = a + bt2
where a = 8.5 m, b = 2.5 m s.2 and t is measured in seconds. What is its velocity at
t = 0 s and t = 2.0 s. What is the average velocity between t = 2.0 s and t = 4.0 s ?
Q.8 Obtain equations of motion for constant acceleration using method of
calculus.
Q.8A ball is thrown vertically upwards with a velocity of 20 m s .1 from
the top of a multi storey building. The height of the point from where the ball is
thrown is 25.0 m from the ground. (a) How high will the ball rise ? and (b) how long
will it be before the ball hits the ground?Take g = 10 m s .
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Q9 A ball is dropped from a height of 90 m on a floor. At each collision with the floor,
the ball loses one tenth of its speed. Plot the speed-time graph of its motion
between t = 0 to 12 s.
Q.10 A car moving along a straight highway with speed of 126 km h.1 is brought to a
stop within a distance of 200 m. What is the retardation of the car (assumed
uniform), and how long does it take for the car to stop ?
Q.11 A motorboat is racing towards north at 25 km/h and the water
current in that region is 10 km/h in the direction of 60° east of south. Find the
resultant velocity of the boat.
Q.12 In a harbour, wind is blowing at the speed of 72 km/h and the flag on the mast of a boat
anchored in the harbour flutters along the N-E direction. If the boat starts moving at a
speed of 51 km/h to the north, what is the direction of the flag on the mast of the boat ?
Q.13 A bullet of mass 0.04 kg moving with a speed of 90 m s-1 enters a
heavy wooden block and is stopped after a distance of 60 cm. What is the average
resistive force exerted by the block on the bullet?
Q.14 Give the magnitude and direction of the net force acting on a stone of mass 0.1 kg,
(a) just after it is dropped from the window of a stationary train,
(b) just after it is dropped from the window of a train running at a constant velocity of 36 km/h,
(c ) just after it is dropped from the window of a train accelerating with 1 m s -2,
Q.15 Two billiard balls each of mass 0.05 kg moving in opposite directions with speed 6 m s -1
collide and rebound with the same speed. What is the impulse imparted to each ball due to the other ?
Q.16 A shell of mass 0.020 kg is fired by a gun of mass 100 kg. If the muzzle speed of the
shell is 80 m s-1, what is the recoil speed of the gun ?
Q.17 A thin circular loop of radius R rotates about its vertical diameter with an angular
frequency . Show that a small bead on the wire loop remains at its lowermost point
for g / R . What is the angle made by the radius vector joining the centre to
the bead with the vertical downward direction for 2g / R ? Neglect friction.
Q.18 A block of mass m = 1 kg,moving on a horizontal surface with speed
vi = 2 ms.1 enters a rough patch rangingfrom x = 0.10 m to x = 2.01 m. The retarding
force Fr on the block in this range is inversely proportional to x over this range,
F=kx

for 0.1 < x < 2.01 m
= 0 for x < 0.1m and x > 2.01 m where k = 0.5 J. What is the final kinetic
energy and speed vf of the block as it
Q.19 An elevator can carry a maximum load of 1800 kg (elevator +
passengers) is moving up with a constant speed of 2 m s .1. The frictional force opposing
the motion is 4000 N. Determine the minimum power delivered by the motor to
the elevator in watts as well as in horse power.
Q.20 A body is initially at rest. It undergoes one-dimensional motion with constant
acceleration. The power delivered to it at time t is proportional to
(i) t1/2 (ii) t (iii) t3/2 (iv) t2
Q.21 A body is moving unidirectionally under the influence of a source of constant power.
Its displacement in time t
is proportional to
(i)
t1/2 (ii) t (iii) t3/2 (iv)t3
Q.22The average depth of Indian Ocean is about 3000 m. Calculate the
fractional compression, V/V, of water at the bottom of the ocean, given that the bulk
modulus of water is 2.2 109 N m–2. (Take g=10 ms-2
Q.23 The edge of an aluminium cube is 10 cm long. One face of the cube is firmly fixed to a
vertical wall. A mass of 100 kg is then attached to the opposite face of the cube. The
shear modulus of aluminium is 25 GPa. What is the vertical deflection of this face?
Q.24 Four identical hollow cylindrical columns of mild steel support a big structure of mass
50,000 kg. The inner and outer radii of each column are 30 and 60 cm respectively.
Assuming the load distribution to be uniform, calculate the compressional strain of
each column.
Q.25 A piece of copper having a rectangular cross-section of 15.2 mm 19.1 mm is pulled in
tension with 44,500 N force, producing only elastic deformation. Calculate the resulting
strain?