Two spheres of same metal have radii a and b. Thet have been connected to a conducting wire. Find the ratio of the electric field intensity upon them.
a/b
b/a
b2 / a
b2/a2
Figure shows the electric lines of forces emerging from a charged body. If the electric field at A and B are EA and EB respectively and if the displacement between A and B is r, then
EA > EB
EA < EB
EA = EB/r
EA = EB / r2
A small piece of metal wire is dragged across the gap between the pole pieces of a magnet in 0.4 sec. If magnetic flux between the pole pieces is known to be 8 × 10-4 Wb, then induced emf in the wire, is
4 × 10-3 V
8 × 10-3 V
20 × 10-3 V
6 × 10-3 V
A Gaussian sphere encloses an electric dipole within it. The total flux across the sphere is
zero
half that due to a single charge
double that due to a single charge
dependent on the position of the dipole
The specific charge of a proton is 9.6 x107 C kg-1 The specific charge of an alpha particle will be
9.6 x107 C kg-1
19.2 x107 C kg-1
4.8 x107 C kg-1
2.4 x107 C kg-1
Point charges + 4q, - q and+ 4q are kept on the x-axis at points x = 0, x = a and x = 2a respectively, then
only- q is in stable equilibrium
all the charges are in stable equilibrium
all the charges are in unstable equilibrium
none of the above
C.
all the charges are in unstable equilibrium
As the net force on each charge is zero, therefore all the charges are in equilibrium. If we were to displace-q to the right, the net force of attraction will be to the right which will displace it further. Therefore, the equilibrium is unstable.
If Ea be the electric field strength of a short dipole at a point on its axial line and Ee that on equilateral line at the same distance, then
Ee = 2Ea
Ea = 2Ee
Ea = Ee
none of these
Charges 4Q, q and Q are placed along x-axis at positions x = 0, x = l/2 and x = l, respectively. Find the value of q so that the force on charge Q is zero:
Q
-Q