Recent questions and answers in Electric Charges and Fields

electric charge Q,Q and -2Q resp. are placed at the three corners of an equilateral triangle of side a . magnitude of the elctrical dipole moment of the system is

answered Mar 23, 2017 by abdulsalamottathil

2 answers

Two identical charged spheres are suspended by strings of equal length . The strings make an angle of $\;60^{0}\;$ with each other . When suspended in a liquid of density $\;0.5 g/cc,\;$ the angle remains the same . The dielectric constant of the liquid is [density of material of sphere is $\;1.5 g/cc\;$ ]

answered Jun 24, 2016 by dongrearchit

2 answers

Six charges are placed at the vertices of a rectangular hexagon as shown in fig. The electric field on the line passing through point O and perpendicular to the plane of the figure as a function of X from point O is (x>>>a)

answered Aug 2, 2015 by pady_1

1 answer

force of interaction between two axial short electric dipoles whose centres are R distance apart varies as

answered May 12, 2015 by sharmaaparna1

1 answer

The time period of a charged simple pendulum in an electric field is:

answered Feb 28, 2014 by thanvigandhi_1

1 answer

An electric line of force in the $xy$ plane is given by equation $x^2+y^2=1$ . A particle with unit positive charge, initially at rest at the point $x = 1, y = 0$ in the $xy$ plane

answered Feb 27, 2014 by thanvigandhi_1

1 answer

Charges 2 q and q are placed at $\;(a , 0)\;and\;(-a , 0)\;.$ The points where electric field is zero will lie in

answered Feb 20, 2014 by yamini.v

1 answer

Four point charges $\;+8 \mu C\;,-1 \mu C\;,-1 \mu C\;and\;+8 \mu C\;$ are fixed at the points $\;-\sqrt{\large\frac{27}{2}} m \;,- \sqrt{\large\frac{3}{2}} m \;,+ \sqrt{\large\frac{3}{2}} m \;and\;+\sqrt{\large\frac{27}{2}} m\;$ respectively on the Y-axis . A particle of mass $\;6\times10^{-4} kg\;$ and charge $\;0.1 \mu C \;$ moves along the - X direction . It's speed at $\;x=+ \infty\;$ is $\;V_{0}\;. \quad \;$ Answer the following question based on the passage . Find the point on the x-axis where electric field is zero .

answered Feb 19, 2014 by yamini.v

1 answer

In a region a horizontal electric field $E = 15N/C$ is present. A ball having charge $2C$ , mass $3kg$ and coefficient of restitution with ground $\;\large\frac{1}{2}\;$ is projected at an angle $\;30^{\circ}\;$ with the horizontal distance travelled by ball from first drop to the second drop

answered Feb 19, 2014 by yamini.v

1 answer

Figure shows a closed dotted surface which intersects a conducting uncharged sphere . If a +ve charge is placed at the point P, the flux of the electric field through the closed surface

answered Feb 19, 2014 by yamini.v

1 answer

A non-conducting disc of radius a and uniform +ve surface charge density $\; \sigma\;$ is placed on the ground with it 's axis vertical . A particle of mass m and +ve charge q is dropped , along the axis of the disc from a height H with zero initial velocity . Find the value of H if the particle just reaches the disk . $\;\large\frac{q}{m}=4 \in_{0} g/\sigma$ . Find the position of particle at which the particle is in equilibrium. Find the energy of the particle at $\;H=\large\frac{a}{\sqrt{3}}\;$ assuming the gravitational energy at $\;H=0\;$ to be zero

answered Feb 19, 2014 by yamini.v

1 answer

A non-conducting disc of radius a and uniform +ve surface charge density $\; \sigma\;$ is placed on the ground with it 's axis vertical . A particle of mass m and +ve charge q is dropped , along the axis of the disc from a height H with zero initial velocity . Find the value of H if the particle just reaches the disk . $\;\large\frac{q}{m}=4 \in_{0} g/\sigma$ . Find the position of particle at which the particle is in equilibrium

answered Feb 18, 2014 by yamini.v

1 answer

A non-conducting disc of radius a and uniform +ve surface charge density $\; \sigma\;$ is placed on the ground with it 's axis vertical . A particle of mass m and +ve charge q is dropped , along the axis of the disc from a height H with zero initial velocity . Find the value of H if the particle just reaches the disk . $\;\large\frac{q}{m}$ $=4 \in_{0} g/\sigma$

answered Feb 18, 2014 by yamini.v

1 answer

The region between two concentric shells of radii a and b $\;(b > a)\;$ contains volume charge density $\;\rho(r)=\large\frac{C}{r}\;$ , where C is a constant and r is the radial distance , as shown in figure . A point charge q is placed at the origin , r=0 . Find the value of C for which the electric field in the region between the spheres is constant.

answered Feb 18, 2014 by yamini.v

1 answer

A rectangular tank of mass $\;m_{0}\;$ and charge Q over it is placed over a smooth horizontal floor. A horizontal electric field E exist in the region . Rain drops are falling vertically in the tank at the constant rate of n drops per second . Mass of each drop is m . find velocity of tank as function of time .

answered Feb 18, 2014 by yamini.v

1 answer

A mass m is to be placed on the rod of length L and pivoted at its centre at a distance x from the left end of the rod so that the system shown in figure remains in equilibrium . Find x (Ignore the force between Q (beaneth q ) and 2q and the force between Q (beneath 2q) and q .

answered Feb 18, 2014 by yamini.v

1 answer

A small ball of mass m and charge +q tied with a string of length l , rotating in a vertical circle under gravity and a uniform horizontal electric field E as shown . The tension in the string will be minimum for

answered Feb 17, 2014 by yamini.v

1 answer

Let $\varepsilon_0$ denote the dimensional formula of the permittivity of vacuum. If M = mass, L = length and T = time and A = electric current then,

answered Feb 15, 2014 by thanvigandhi_1

1 answer

A particle of mass m and charge +q is projected from the origin with a speed v at an angle $\;30^{0}\;$ with the horizontal into an electric field of intensity E directed downward . Equation of trajectory of particle is . Neglect gravity

answered Feb 14, 2014 by yamini.v

1 answer

A particle of charge -q and mass m moves in a circle of radius r arround an infinitely long line charge of linear density $\;+\lambda\;$ . Then time period will be

answered Feb 14, 2014 by yamini.v

1 answer

A 10.0 Kg block carrying a charge 100 $\;\mu C\;$ is connected to a spring for which $\;K=100 N/m\;$ . The block lies on a frictionless horizontal track , and the system is immersed in a uniform electric field $\;E=5\times10^{5}\;V/m\;$ , directed as shown in figure . If the block is released from rest when the spring is amount does the spring expand

answered Feb 14, 2014 by yamini.v

1 answer

A point charge q is placed on the top of a cone of serni-vertex angle $\;\theta\;$ Find the electric flux through the base of the cone

answered Feb 14, 2014 by yamini.v

1 answer

A particle of mass m and charge q is fastened to one end of a string of length l . The other end of the string is fixed to the point O . The whole system lies on a frictionless horizontal plane . Initially , the mass is at rest at A . A uniform electric field in the direction shown is the switched on . Then speed of the particle at B and tension in the string are

answered Feb 13, 2014 by yamini.v

1 answer

Six charges are placed at the certices of a regular hexagon as shown in the figure . The electric field on the line passing through point O and perpendicular to the plane of the figure as a function of distance x from point O is $\;(x > > a)$

answered Feb 12, 2014 by yamini.v

1 answer

Two point charges a and b whose magnitudes are same positioned at a certain distance along the positive x-axis from each other . a is at origin and b is at a distance $\;x_{0}\;$ from a . Graph is drawn between electrical field strength and distance x from a . E is taken positive if it is along the line joining from a to b . Then

answered Feb 12, 2014 by yamini.v

1 answer

A uniform electric field of strength $\;\overrightarrow{E}\;$ exists in a region . An electron enters a point $A$ with velocity $v$ as shown . It moves through the electric field and reaches at point $B$ . Velocity of particle at $B$ is $2v$ at $30^{\circ}\;$ with x - axis . Then electric field $\;\overrightarrow{E}\;$ is

answered Feb 12, 2014 by yamini.v

1 answer

In the diagram shown , the charge +Q is fixed another charge +2q and mass M is projected from a distance R from the fixed charge . Minimum separation between the charges if the velocity becomes $\;\large\frac{1}{\sqrt{3}}\;$ times of the projected velocity , at this moment

answered Feb 12, 2014 by yamini.v

1 answer

An electric dipole of dipole moment P is placed in a uniform electric field E in stable equilibrium position . It's moment of inertia about the centroidal axis is I . If it is displaced slightly from it mean position find the period of small oscillations .

answered Feb 12, 2014 by yamini.v

1 answer

Find the torque due to an external uniform electric field on a dipole of dipole moment $\;\overrightarrow{P}$

answered Feb 11, 2014 by yamini.v

1 answer

A charged particle of mass m and charge q is released from rest from the position $\;(x_{0} ,0)\;$ in a uniform electric field $\;E_{0} \hat{j}\;.$ The angular momentum of particle about origin

answered Feb 7, 2014 by yamini.v

1 answer

An electric dipole is placed perpendicular to an infinite line of charge at some distance as shown in figure . Identify the correct statement

answered Feb 7, 2014 by yamini.v

1 answer

Potential due to a system at polar coordinates $\;(r , \theta)\;$ is given by $\;\large\frac{\alpha \;cos \theta}{r^2}\;$ Find the magnitude of electric field at that point if $\;\alpha=3 Vm^2\;,(r , \theta)=(\sqrt{3} ,tan^{-1} \large\frac{1}{\sqrt{2}}).$

answered Feb 7, 2014 by yamini.v

1 answer

A uniform electric field exists in x -y plane. The potential of points $\;A (2m ,2m) , B (-2m ,2m)\;and\; C(2m ,4m)\;$ are 4V , 16V and 12V respectively . The electric field is

answered Feb 7, 2014 by yamini.v

1 answer

The electric field on the axis of a dipole of dipole moment $\;\overrightarrow{P}\;$ at a distance x from the line joining the charges and $\;(x > > d)\;$

answered Feb 7, 2014 by yamini.v

1 answer