Download Holiday Home work By Mrs. Dikshita Saikia

HOLIDAY HOMEWORK
CLASS- IX (PHYSICS)
1. Answer all the textbook questions of chapter “Motion”?
2. Under what condition is the magnitude of average velocity of an object equal to its average
speed?
(1)
3. What is odometer?
(1)
4. What is the difference between distance & displacement?
(1)
5. Represent two forces one of 50N due to south & the other of 25N due to east, acting
simultaneously on a particle?
(1)
6. What is free fall? Write the equations of motion of an object if it is falling freely under
gravitational pull?
(1+4=5)
7. An object has moved through a distance. Can it have zero displacement? If yes, justify your
answer?
(2)
8. What is retardation? Explain briefly?
(2)
9. Differentiate between uniform linear motion & uniform circular motion?
(2)
10. Give any four examples of uniform circular motion?
(2)
11. Find the initial velocity of a car which is stopped in 10 sec by applying brake? Given the
retardation is -2.5 m/s2?
(3)
12. A train is moving on a straight track at a speed of 72 km/hr & passes a pole in 3 sec. Find the
time taken to pass the bridge of length 540m?
(3)
13. A train starts from rest and attains a speed of 54 km/hr in 10 sec. Calculate a) acceleration & b)
distance covered by the train?
(2+2=4)
14. A body starting from rest travels with uniform acceleration. If it travels 100m in 5 sec, what is
the value of acceleration?
(3)
PROJECT WORK (MARK=10)
Make a project report on circular motion with appropriate terms & figures.
HOLIDAY HOMEWORK
CLASS- XII (PHYSICS)
15. Answer all the textbook questions of chapter-2 “Electrostatic Potential & Capacitance”?
16. In which orientation a dipole placed in a uniform electric field is in – a) stable, b) unstable
equilibrium?
17. Two point charges having equal magnitudes separated by 1m distance experienced a force of
8N. What will be the force experienced by them if they are held in water at same distance
(given dielectric constant K=80 in water)?
18. Two small identical dipoles AB & CD having each of dipole moment “p” are kept at an angle of
1200. What is the resultant dipole moment of this combination? If the system is subjected to
electric field “E” directed along +X axis, what is the magnitude and direction of the torque
acting on it?
19. Plot a graph showing the variation of Coulomb’s force Vs 1/r2, where r is the distance between
the two charges of each pair of charges (1 µC, 2 µC) & (1 µC, -3 µC). Interpret the graph obtain?
20. A dipole with a dipole moment “p” is in stable equilibrium in an electrostatic field “E”. Find
the work done in rotating this dipole to its position of unstable equilibrium?
21. A dipole is present in an electrostatic field of magnitude 106N/C. If the work done in rotating it
from stable to unstable equilibrium is 2 x 10-23 J. find the magnitude of dipole moment?
22. Define a dielectric constant of a medium? What is its unit?
23. If the radius of Gaussian surface enclosing a charge is halved, how does the electric flux
through the Gaussian surface change?
24. Two charged conducting spheres of radii are r1 & r2 connected to each other by a wire. Find the
ratio of electric field at the surfaces of the two spheres?
25. A point charge causes an electric flux - 3x10-14 Nm2/C to pass through a spherical Gaussian
surface. a) Calculate the value of the point charge? b) If the radius of the Gaussian surface is
double, how much flux would pass through the surface?
26. Two charges of magnitudes -2q and +q are located at points (a, 0) & (4a, 0) respectively. What is
the electric flux due to these charges through a sphere of radius “3a” with its centre at the
origin?
27. Can two equipotential surfaces intersect each other?
28. Name the physical quantity whose S.I. unit is J/C? Is it vector or scalar?
29. What is the work done in moving a test charge”q” through a distance of 1cm along the
equatorial axis of an electric dipole?
30. Draw three equipotential surfaces corresponding to a field that uniformly increases in
magnitude but remain constant along Z-direction. How are these surfaces different from that of
a constant electric field along Z-direction?
31. Two charges of 5 nC & -2 nC are placed at points (5cm, 0, 0) & (23cm, 0, 0) in region of space
where there is no other external field. Calculate the electrostatic potential energy of this system?
32. A wire AB is carrying a steady current of 12A & is lying on the table. Another wire CD carrying
current 5A is held above AB at a height of 1mm. Find the mass per unit length of the wire CD,
so that it remains suspended at its position when left free. Give the direction of current flowing
in CD with respect to that in AB?
33. A metal plate is introduced between the plates of a charged parallel plate capacitor. What is its
effect on the capacitance of the capacitor?
34. A parallel plate capacitor is charged to potential difference V by a DC source. The capacitor is
then disconnected from the source. If the distance between the plates is doubled, state with
reason how the following will change :a) Electric field between the plates
b) capacitance
c) energy stored in the capacitor.
35. Show that the effective capacitance C of a series combination of three capacitor C1,C2,C3 is given
by –
36. The equivalent capacitance of the combination between points A & B in the given figure is 4µF
a) Calculate capacitance of the capacitor C?
b) Calculate charge on each capacitor if 12V is
connected across A & B?
c) Calculate potential across each capacitor?
37. Two identical parallel plate capacitors C1 & C2 have capacitance C each. The space between the
plates is filled with dielectric (as shown in figure). If the two capacitors still have equal
capacitance, obtain the relation between dielectric constants K,K1 & K2?