Previous Year Questions

## Electric Charges And Fields

- It's good to be already prepared. Go through the previous year questions.
1
A spherical conductor of radius 10 cm has a charge of distributed uniformly. What is the magnitude of electric field at a point from the centre of the sphere?
A
B
C
D
Two point charges A and B, having charges +Q and -Q respectively, are placed at certain distance apart and force acting between them is F. If 25% charge of A is transferred to B, then force between the charges becomes
A
B
C
D
A hollow metal sphere of radius R is uniformly charged. The electric field due to the sphere at a distance r from the centre
A
Increases as r increases for and for
B
Zero as r increases for , decreases as r increases for
C
Zero as r increases for , increases as r increases for
D
Decreases as r increases for and for
An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. The direction of electric field is now reversed, keeping its magnitude the same. A proton is allowed to fall from rest in it through the same vertical distance h. The time of fall of the electron, in comparison to the time of fall of the proton is?
A
times greater
B
Smaller
C
Equal
D
times greater
Suppose the charge of a proton and an electron differ slightly. One of them is -e, the other is . If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (much greater than atomic size) apart is zero, then is of the order of [Given mass of hydrogen ]
A
B
C
D
A dipole of moment p is placed in uniform electric field E then torque acting on it is given by : -
A
B
C
D
An electric dipole is placed at an angle of with an electric field intensity . It experiences a torque equal to The charge on the dipole, if the dipole length is , is :
A
B
C
D
Electric field at center  of semicircle of radius having linear charge density is given as :
A
B
C
D
Two identical charged spheres suspended from a common point by two massless strings of lengths , are initially at a distance apart because of their mutual repulsion. The charges begin to leak from both the spheres at a constant rate. As a result, the spheres approach each other with a velocity . Then varies as a function of the distance between the spheres as:
A
B
C
D