Question 3

# Two charges 2 μC and −2 μC are placed at points A and B 6 cm apart.

(a) Identify an equipotential surface of the system.

(b) What is the direction of the electric field at every point on this surface?

(a) Identify an equipotential surface of the system.

(b) What is the direction of the electric field at every point on this surface?

Answer

**(a) **The situation is represented in the given figure.

An equipotential surface is the plane on which total potential is zero everywhere. This plane is normal to line AB. The plane is located at the mid-point of line AB because the magnitude of charges is the same.

**(b) **The direction of the electric field at every point on this surface is normal to the plane in the direction of AB.

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What is the force between two small charged spheres having charges of 2 x 10

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A polythene piece rubbed with wool is found to have a negative charge of 3 × 10

^{−7}C.(a) Estimate the number of electrons transferred (from which to which?)

(b) Is there a transfer of mass from wool to polythene?

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A parallel plate capacitor with air between the plates has a capacitance of 8 pF (1pF = 10

^{-12}F). What will be the capacitance if the distance between the plates is reduced by half, and the space between them is filled with a substance of dielectric constant 6? - Q:-
A 600 pF capacitor is charged by a 200 V supply. It is then disconnected from the supply and is connected to another uncharged 600 pF capacitor. How much electrostatic energy is lost in the process?

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A regular hexagon of side 10 cm has a charge 5 µC at each of its vertices. Calculate the potential at the centre of the hexagon.

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A point charge +10 μC is a distance 5 cm directly above the centre of a square of side 10 cm, as shown in Fig. 1.34. What is the magnitude of the electric flux through the square? (Hint: Think of the square as one face of a cube with edge 10 cm.)

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A point charge of 2.0 μC is at the centre of a cubic Gaussian surface 9.0 cm on edge. What is the net electric flux through the surface?

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The electrostatic force on a small sphere of charge 0.4 μC due to another small sphere of charge − 0.8 μC in air is 0.2 N.

(a) What is the distance between the two spheres?

(b) What is the force on the second sphere due to the first?

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A magnetic field set up using Helmholtz coils (described in Exercise 4.16) is uniform in a small region and has a magnitude of 0.75 T. In the same region, a uniform electrostatic field is maintained in a direction normal to the common axis of the coils. A narrow beam of (single species) charged particles all accelerated through 15 kV enters this region in a direction perpendicular to both the axis of the coils and the electrostatic field. If the beam remains undeflected when the electrostatic field is 9.0 x 10

^{-5}V m^{-1}, make a simple guess as to what the beam contains. Why is the answer not unique? - Q:-
What is the force between two small charged spheres having charges of 2 x 10

^{-7}C and 3 x 10^{-7}C placed 30 cm apart in air? - Q:-
A parallel plate capacitor with air between the plates has a capacitance of 8 pF (1pF = 10

^{-12}F). What will be the capacitance if the distance between the plates is reduced by half, and the space between them is filled with a substance of dielectric constant 6? - Q:-
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^{-4}°C^{-1}. - Q:-
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that the capacitance of a spherical capacitor is given by

where

*r*1 and*r*2 are the radii of outer and inner spheres, respectively. - Q:-
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An infinite line charge produces a field of 9 × 10

^{4}N/C at a distance of 2 cm. Calculate the linear charge density. - Q:-
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(a) their momenta,

(b) the energy of the photon, and

(c) the kinetic energy of electron.

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Two moving coil meters, M

_{1}and M_{2}have the following particulars:R

_{1}= 10 Ω, N_{1}= 30,A

_{1 }= 3.6 x 10^{-3}m2, B1 = 0.25 TR

_{2}= 14 Ω, N_{2}= 42,A

_{2}= 1.8 x 10-3 m2, B_{2}= 0.50 T(The spring constants are identical for the two meters).

Determine the ratio of (a) current sensitivity and (b) voltage sensitivity of M

_{2}and M_{1}.

Itabur Rahman
2019-06-28 17:49:42

Where is the figure??

Vishawjeet
2019-05-17 13:19:51

Where is the figure??

virendra veer chaturvedi
2016-08-10 19:53:04

niceee....

usha
2016-08-08 04:44:37

bad site

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