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The linear charge density on upper half of segment of ring is $λ$ and at lower half it is $- λ$ . The direction of electric field at centre $O$ of ring is

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Important Questions on Electrostatics

EASY

Physics>Electricity and Magnetism>Electrostatics>Electric Field

Two charged thin infinite plane sheets of uniform charge density

σ_{+}

and

σ_{-}

, where

|σ_{+}| > |σ_{-}|

, intersect at the right angle. Which of the following best represents the electric field lines for the system:

HARD

Physics>Electricity and Magnetism>Electrostatics>Electric Field

A particle of mass

m

and charge

q

is released from rest in a uniform electric field. If there is no other force on the particle, the dependence of its speed

v

on the distance

x

travelled by it is correctly given by (graphs are schematic and not drawn to scale)

MEDIUM

Physics>Electricity and Magnetism>Electrostatics>Electric Field

A particle of mass

m

and charge

q

is placed at rest in uniform electric field

E

and then released. The kinetic energy attained by the particle after moving a distance

y

EASY

Physics>Electricity and Magnetism>Electrostatics>Electric Field

A spherical conductor of radius

10 cm

has a charge of

3.2 \times 10^{- 7} C

distributed uniformly. What is the magnitude of electric field at a point

15 cm

from the centre of the sphere?

(\frac{1}{4 π ε_{0}} = 9 \times 10^{9} {Nm}^{2} C^{- 2})

MEDIUM

Physics>Electricity and Magnetism>Electrostatics>Electric Field

Two parallel infinite line charges with linear charge densities

+ λ C m^{- 1}

and

- λ C m^{- 1}

are placed at a distance of

2 R

in free space. What is the electric field mid-way between the two-line charges?

EASY

Physics>Electricity and Magnetism>Electrostatics>Electric Field

Charges $Q_{1}$ and $Q_{2}$ are at points $A$ and $B$ of a right-angled triangle $O A B$ . The resultant electric field at point $O$ is perpendicular to the hypotenuse, then $Q_{1} / Q_{2}$ is proportional to:

Question Image

HARD

Physics>Electricity and Magnetism>Electrostatics>Electric Field

Three charged particles $A, B$ and $C$ with charges $- 4 q, 2 q$ and $- 2 q$ are present on the circumference of a circle of radius $d .$ The charged particles $A, C$ and centre $O$ of the circle formed an equilateral triangle as shown in the figure. The electric field at the point $O$ is
Question Image

MEDIUM

Physics>Electricity and Magnetism>Electrostatics>Electric Field

There is a uniform electric field of strength

10^{3} V m^{- 1}

along the

Y -

axis. A particle of mass

1 g

and charge

10^{- 6} C

is projected into the field from the origin along the

+ ve X

-axis with a velocity of

40 m s^{- 1}

. Then the magnitude of its velocity after

30 seconds

will be (neglect gravitation)

EASY

Physics>Electricity and Magnetism>Electrostatics>Electric Field

The bob of a simple pendulum has mass

2 g

and a charge of

5.0 μ C .

It is at rest in a uniform horizontal electric field of intensity

2000 V / m

At equilibrium, the angle that the pendulum makes with the vertical is:

(t a k e g = 10 m / s^{2})

HARD

Physics>Electricity and Magnetism>Electrostatics>Electric Field

Four point charges

- q, + q, + q

and

- q

are placed on y-axis at

y = - 2 d, y = - d,

and

y = + 2 d,

respectively. The magnitude of the electric field

E

at a point on the x-axis at

x = D,

with

D ≫ d,

will behave as:

EASY

Physics>Electricity and Magnetism>Electrostatics>Electric Field

Two metal plates having a potential difference of

800 V

are

2 cm

apart. It is found that a particle of mass

1.96 \times 10^{- 15} kg

remains suspended in the region between the plates. The charge on the particle must be (

e =

elementary charge)

HARD

Physics>Electricity and Magnetism>Electrostatics>Electric Field

A wire of length

L = 20 c m

is bent into a semi-circular arc and the two equal halves of the arc are uniformly charged with charges

+ Q

and

- Q

as shown in the figure. The magnitude of the charge on each half is

|Q| = 10^{3} ε_{0}

, where

ε_{0}

is the permittivity of free the space. The net electric field at the centre

O

MEDIUM

Physics>Electricity and Magnetism>Electrostatics>Electric Field

A point charge of

50 μ C

is placed in the

X Y

plane at a location with radius vector

{\vec{r}}_{0} = 2 \hat{i} + 3 \hat{j} m

The electric field strength and its magnitude at a point with radius vector

\vec{r} = 8 \hat{i} - 5 \hat{j} m

(ε_{o} = 8.85 \times 10^{- 12} C^{2} N - m^{- 2})

HARD

Physics>Electricity and Magnetism>Electrostatics>Electric Field

A charged particle (mass $m$ and charge $q$ ) moves along $X$ axis with velocity $V_{0}$ . When it passes through the origin it enters a region having uniform electric field $\vec{E} = - E \hat{j}$ which extends upto $x = d$ . Equation of path of electron in the region $x > d$ is:

Question Image

MEDIUM

Physics>Electricity and Magnetism>Electrostatics>Electric Field

An infinite line of charge with uniform line charge density of

1 C m^{- 1}

is placed along the

y

-axis. A charge of

1 C

is placed on the

x

-axis at a distance of

d = 3 m

from the origin. At what distance

(r)

from the origin on the

x

-axis, the total electric field is zero.

N

(Assume

0 < r < d

)

HARD

Physics>Electricity and Magnetism>Electrostatics>Electric Field

As shown in the figure, a point charge

q_{1} = + 1 \times 10^{- 6} C

is placed at the origin in

x y

-plane and another point charge

q_{2} = + 3 \times 10^{- 6} C

is placed at the coordinate

(10, 0) .

In that case, which of the following graph

(s)

shows most correctly the electric field vector in

E_{x}

x

-direction ?

EASY

Physics>Electricity and Magnetism>Electrostatics>Electric Field

Two identical charged spheres separated by a distance repel each other with a force

F

. If

10 %

of electrons are transferred from one sphere to the other than the force between them becomes

MEDIUM

Physics>Electricity and Magnetism>Electrostatics>Electric Field

A simple pendulum of length

L

is placed between the plates of a parallel plate capacitor having electric field

E

, as shown in figure. Its bob has mass

m

and charge

q

. The time period of the pendulum is given by:
Question Image

EASY

Physics>Electricity and Magnetism>Electrostatics>Electric Field

The electric field in a certain region is acting radially outward and is given by

E = A r

. A charge contained in a sphere of radius

a

centred at the origin of the field will be given by

MEDIUM

Physics>Electricity and Magnetism>Electrostatics>Electric Field

Two point charges

q_{1} (\sqrt{10} μC)

and

q_{2} (- 25 μC)

are placed on the

x

-axis at

x = 1 m

and

x = 4 m

respectively. The electric field

(in V m^{- 1})

at a point

y = 3 m

y

-axis is,

[Take \frac{1}{4 π ϵ_{0}} = 9 \times 10^{9} N m^{2} C^{- 2}]

The linear charge density on upper half of segment of ring is λ and at lower half it is -λ . The direction of electric field at centre O of ring is

Important Questions on Electrostatics

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The linear charge density on upper half of segment of ring is $λ$ and at lower half it is $- λ$ . The direction of electric field at centre $O$ of ring is