HARD
12th West Bengal Board
IMPORTANT
Earn 100

Two identical conducting balls A and B have positive charges q1 and q2 respectively but q1q2. The balls are brought together so that they touch each other and kept in thin original positions. The force between them is

33.33% studentsanswered this correctly

Important Questions on Interaction of Charged Particles, Electric Field and Potential

EASY
12th West Bengal Board
IMPORTANT
A conductor has given a charge -3×10-7C by transferring electrons. Mass increase (in Kg) of the conductor and the number of electrons added to the conductor are respectively.
MEDIUM
12th West Bengal Board
IMPORTANT
A charge Q is placed at each of the opposite corners of a square. A charge q is placed at each of the other two corners. If the net electrical force on Q is zero, then the Qq equals
MEDIUM
12th West Bengal Board
IMPORTANT
Two equal charges are separated by a distance d. A third charge placed on a perpendicular bisector at x distance from centre will experience maximum coulomb force, when
HARD
12th West Bengal Board
IMPORTANT
The bob of simple pendulum is hanging vertically down from a fixed identical bob by means of a string of length l. If both bobs are charged with a charge q each, time-period of the pendulum is (ignore the radii of the bobs)
HARD
12th West Bengal Board
IMPORTANT
A wooden block performs SHM on a frictionless surface with frequency v0. The block carries a charge +Q on its surface. If now a uniform electric field E is switched on as shown in Fig. 2.121, then the SHM of the block will be

Question Image

MEDIUM
12th West Bengal Board
IMPORTANT
A few electric field lines for a system of two charges Q1 and Q2 fixed at two different points on the X-axis are shown in the figure, Fig. 2.122 These lines suggest that

Question Image

EASY
12th West Bengal Board
IMPORTANT
Charges are placed on the vertices of a square as shown in Fig. 2.123. Let E be the electric field and V the potential at the centre. If the charges on A and B are interchanged with those on D and C respectively, then

Question Image

MEDIUM
12th West Bengal Board
IMPORTANT
The potential at a point x (measured in μm) due to some charges situated on the X -axis is given by 

V(x)=20x2-4 volt.

The electric field E at x=4 μm is given by