Five capacitors, each of capacitance value C are connected as shown in the figure. The ratio of
capacitance between P and R, and the capacitance between P and Q is
3 : 1
5 : 2
2 : 3
1 : 1
Two infinitely long parallel conducting plates having surface charge densities + σ and σ respectively, are separated by a small distance. The medium between the plates is vacuum. lf ε0 is the dielectric permittivity of vacuum, then the electric field in the region between the plates is
0 volt/metre
volt/metre
volt/metre
volt/metre
Two concentric conducting thin spherical shells A and B having radii rA and rB ( rB > rA ) are charged to QA and - QB (). The electrical field along a line, (passing through the centre is)
Four point + ve charges of same magnitude (Q) are placed at four corners of a rigid square frame as shown in figure. The plane of the frame is perpendicular to Z-axis. If a -ve point charge is placed at a distance z away from the above frame ( z < < l ) then
-ve charge oscillates along the Z-axis
it moves away from the frame
it moves slowly towards the frame and stays in the plane of the frame
it moves slowly towards the frame and stays in the plane of the frame
Equipotential surfaces associated with an electric field which is increasing in magnitude along the x-direction are
planes parallel to yz - plane
planes parallel to xz-plane
planes parallel to xz-plane
coaxial cylinders of increasing radii around the x-axis
A 40F capacitor in a defibrillator is charged to 3000 V. The energy stored in the capacitor is sent through the patient during a pulse of duration 2 ms. The power delivered to the patient is
45 kW
90 kW
180 kW
360 kW
In the basic CsCl crystal structure, Cs+ and Cl- ions are arranged in a bcc configuration as shown in the figure. The net electrostatic force exerted by the eight Cs- ions on the Cl- ion is
zero
An electron is travelling along the x-direction. It encounters a magnetic field in the y-direction. Its subsequent motion will be
straight line along the x-direction
a circle in the xz plane
a circle in the yz plane
a circle in the xy plane
An electron having charge 'e' and mass m is moving in a uniform electric field E. Its acceleration will be
In the given figure, the capacitance C1, C3, C4 and C5 have a capacitance 4 μF each. If the capacitor C2 has a capacitance 10 μF, then effective capacitance between A and B will be
2 μF
6 μF
4 μF
8 μF
C.
4 μF
Capacitance of capacitors C1 , C3 , C4 , C5 = 4 μF each and capacitance of capacitor C2 = 10 μF.
If a battery is applied across A and B, the points b and c will be at the same potential ( since C1 = C4 = C3 = C5 = 4 μF )
Therefore no charge flows through C2.
We have the capacitors C1 and C5 in series.
Therefore their equivalent capacitance
C'' =
=
C" = 2 μF
Now C' and C" are in parallel. Therefore capacitance between A and B
= C' + C"
= 2 + 2
= 4 μF