CBSE Test Paper (Electrostatics) (Class - XII Physics) - Class 12 PDF Download

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CBSE TEST PAPER-01 
CLASS - XII PHYSICS (Unit – Electrostatics) 
1. Show does the force between two point charges change if the dielectric constant
of the medium in which they are kept increase?
[3] 
2. A charged rod P attracts rod R where as P repels another charged rod Q. What
type of force is developed between Q and R?
[1] 
3. A free proton and a free electron are placed in a uniform field. Which of the two
experience greater force and greater acceleration?
[2] 
4. No two electric lines of force can intersect each other?  Why? [2] 
5. A particle of mass m and charge q is released form rest in  a uniform electric
field of intensity E. calculate the kinetic energy it attains after moving a distance
s  between the plates?
[3] 
6. Two point charges +q and +9q are separated by a distance of 10 a. Find the point
on the line joining the two changes where electric field is zero?
[3] 
7.
Define the term dipole moment P

 
 of an electric dipole indicating its direction. 
Write its S.I unit. An electric dipole is placed in a uniform electric field E


. Deduce 
the expression for the Torque acting on it.
[3] 
8.
(1) The electric field E


 due to a point change at any point near to it is defined 
as: 
q c 
F
E Lim
q
?
=




 where q is the test charge and F


 is the force acting on it. 
What is the significance of 
lim
q o ?
 in this expression?
(2) Two charges each 2 x 10
-7
 C but opposite in sign forms a system. These 
charges are located at points A (0,0, -10) cm and B(0,0, +10) cm 
respectively. What is the total charge and electric dipole moment of the 
system? 
[5] 
9. (a) Sketch electric lines of force due to (i) isolated positive change (ie q>0) and
(ii) isolated negative change ( ie q<0)   
(b) Two point changes q and –q are placed at a distance 2a apart. Calculate the 
electric field at a point P situated at a distance r along the perpendicular 
bisector of the line joining the charges. What is the field when r >> a? 
[5]