Suppose the charge of a proton and an electron differ slightly. One of them is $$-$$e, the other is (e + $$\Delta $$e). If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (musch greater than atomic size) apart is zero, then $$\Delta $$e is of the order of
[Given : mass of hydrogen mh = 1.67 $$ \times $$ 10$$-$$27 kg]
A
10$$-$$23 C
B
10$$-$$37 C
C
10$$-$$47 C
D
10$$-$$20 C
2
NEET 2017
MCQ (Single Correct Answer)
+4
-1
The diagrams below show regions of equipotentials.
A positive charge is moved from A to B in each diagram.
A
In all the four cases the work done is the same.
B
Minimum work is required to move q in figure(I).
C
Maximum work is required to move q in figure (II).
D
Maximum work is required to move q in figure (III)
3
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
An electric dipole is placed at an angle of 30o with an electric field intensity 2 $$ \times $$ 105 N C$$-$$1. It experiences a torque equal to 4 N m. The charge on the dipole, if the dipole length is 2 cm, is
A
8 mC
B
2 mC
C
5 mC
D
7 $$\mu $$C
4
NEET 2016 Phase 1
MCQ (Single Correct Answer)
+4
-1
Two identical charged spheres suspended from a common point by two massless strings of lengths $$l$$, are initially at a distance d(d < < $$l$$) 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 v. Then v varies as a function of the distance x between the spheres, as
