  Types Of Questions

## Electric Charges And Fields

- Wondering what kind of questions that can be asked in next exam? Here you go!
1
Single choice correct
Two identical pendulums and are suspended from the same point. Both are given a positive charge, with having more charge than . They diverge and reach equilibrium with the strings of pendulums and making angles and with the vertical respectively. Then:
A
>
B
<
C
D
the tension in A is greater than that in B
An electron moves with a velocity in an electric field . If the angle between and is neither 0 nor , then the path followed by the electron is a(an):
A
straight line
B
circle
C
ellipse
D
parabola
A charge is divided into two parts and such that they experience maximum force of repulsion when separated by certain distance. The ratio of and is :
A
1 : 1 : 2
B
1 : 2 : 2
C
2 : 2 : 1
D
2 : 1 : 1
2
Multiple choice correct
A spherical metal shell A of radius and a solid metal sphere of radius are kept far apart and each is given ''. Now they are connected by thin metal wire. Then:
This question has multiple correct options
A
B
C
D
Two non-conducting spheres of radii and carrying uniform volume charge densities and, respectively, are placed such that they partially overlap, as shown in the figure. At all points in the overlapping region:

This question has multiple correct options
A
the electrostatic field is zero
B
the electrostatic potential is constant
C
the electrostatic field is constant in magnitude
D
the electrostatic field has same direction
A particle of mass and charge is fastened to one end of a light string of length . The other end of the string is fixed to the point . The whole system lies on a frictionless horizontal plane. Initially, the mass is at rest at . A uniform electric field in the direction shown is switched on. Then,
This question has multiple correct options
A
the speed of the particle when it reaches is
B
the speed of the particle when it reaches is
C
the tension in the string when particles reaches is
D
the tension in the string when the particle reaches is zero
3

### Numerical Type I

A circular ring of radius with uniform positive charge density per unit length is fixed in the Y-Z plane with its centre at the origin . A particle of mass and positive charge is projected from the point on the positive X-axis directly towards , with initial velocity . The smallest value of the speed such that the particle does not return to is . Find
A point charge & mass experiences a force of at a point at a distance from a long infinite uniformly charged wire. If it is released its speed is  when it is at a distance from wire. Find .
The length of each side of a cubical closed surface is . If charge is situated on one of the vertices of the cube, then if the flux passing through shaded face of the cube is . Find :
4

### Numerical Type II

A particle of mass and charge moves along a diameter of a uniformly charged sphere of radius and carrying a total charge . The frequency of S.H.M of the particle if the amplitude does not exceed , is . Find .
A particle of mass and negative charge is thrown in a gravity free space with speed from the point in the large nonconducting charged sheet with surface charge density , as shown in figure. The maximum distance from on sheet where the particle can strike is . Find .
Two point charges q and q are placed at a distance 'd' apart as shown in the figure. The electric field intensity is zero at a point 'P' on the line joining them as shown. If the ratio is . Find the value of .
5

### Matrix Match Type I

Figure in column 1 shows some fixed charge systems  and movable point charge , match the options in column 1 for equilibrium of in the given direction.
List 1Equilibrium in x-direction

(system consist of a uniformly charged
fixed non-conducting spherical shell and neglect effect of induction)
(A uniformly charged fixed ring)

Equilibrium of q charge in given direction.     List 2unstableaccelerating (non-equilibrium)stableneutral
Inside a neutral metallic spherical shell, a charge is placed, and outside the shell, a charge is placed.
List 1If is at the center of the shellIf is not at the center of the shellIf the position of is changed within the shell keeping fixedIf the position of is changed outside keeping fixed inside at any point
List 2Electric field inside the shell remains zeroElectric field inside the shell remains nonzeroElectric field inside changesElectric field outside changes
Consider three point charges , and and four closed surfaces , and .
List 1Net flux through Net flux through Net flux through Net flux through
List 2zerononzero
6

### Matrix Match Type II

Five identical charges are kept at live vertices of a regular hexagon, Match the following two columns at centre of the hexagon, If in the given situation electric field at centre is E, Then
List 1If charge at B is removed then electric field will becomeIf charge at C is removed then electric field wiIl becomeIf charge at D is removed then electric field will becomeIf charges at B and C both are removed then electric field will become
List 22EEZero
Dotted surfaces are Gaussian surfaces and solid surfaces are material bodies. All the surfaces are spherical.
List 1Electric field at point A is zeroElectric field at point B is zeroFlux through surface 1 is zeroFlux through surface 2 is zero
List 2A dipole is placed as shownA point charge kept at centre of neutral conducting shell as shownA dipole kept at centre of neutral conducting shell as shownA point charge kept outside of neutral conducting shell as shown    Graph between electric potential and the x-coordinate is given and the electric field is along the x-axis.Then find total charge in various cubes placed with one edge along positive x-axis.
List 1Cube of 1m edge with one corner at originCube of 1m edge which lies between x =3 to x = 4Cube of 2m edge placed between the coordinate x = 4 to x = 6Cube of 6m edge placed between the coordinate x = 0 to x = 6
List 2PositiveNegativeZeroMagnitude of charge is units
7

### Passage Type

The electric dipole moment is:

A
B
C
D

The potential energy of the dipole in the equilibrium position is :

A
B
C
D
The flux of through this surface is given by :
A
B
C
D