Electric fields and charges practice · Mixed difficulty

There is an electric field ${E}$ in $x$-direction. If the work done on moving a charge of $0.2 \mathrm{C}$ through a distance of $2 \mathrm{~m}$ along a line making an angle $60^{\circ}$ with $x$-axis is $1 \mathrm{~J}$, then what is the value of $E$?

If an electron is accelerated by $8.8 \times 10^{14} m / s ^2$, then electric field required for acceleration is (given specific charge of the electron $=1.76 \times 10^{11} Ckg ^{-1}$ )

A polythene piece, rubbed with wool, is found to have negative charge of $4 \times {10^{ - 7}}$C. the number of electrons transferred from wool to polythene is

The electric field intensity which would be just sufficient to balance the weight of a charge $100\, \mu \mathrm{C}$ and mass $10 \mathrm{~g}$ is _____ N/C. (Take $g=10 \mathrm{~m} \mathrm{~s}^{-2}$ )

The magnitude of electric force, F is

A negatively charged object X is repelled by another charged object Y. However an object Z is attracted to object

Y. Which of the following is the most possibility for the charge of object Z?

Statement-1: An electric dipole placed in the electric field of a point charge can never experience zero resultant force.
Statement-2: Electric field of a point charge is non uniform.

Assertion: On disturbing an electric dipole in stable equilibrium in an electric field, it returns back to its stable equilibrium orientation.
Reason: A restoring torque acts on the dipole on being disturbed from its stable equilibrium.

Flux coming out from a unit positive charge enclosed in air is

The electric field required to keep a water drop of mass m just to remain suspended, when charged with one
electron, is

A charged particle of mass $5 \times {10^{ - 5}}kg$ is held stationary in space by placing it in an electric field of strength ${10^7}N{C^{ - 1}}$ directed vertically downwards. The charge on the particle is

According to Gauss’ Theorem, electric field of an infinitely long straight wire is proportional to

Electric field in a region is $\vec E = 3\hat j\,N/C$. Equipotential surfaces are parallel to

A current carrying wire in the neighborhood produces

A force $F$ acts between sodium and chlorine ions of salt (sodium chloride) when put 1cm apart in air. The permittivity of air and dielectric constant of water are ${\varepsilon _0}$ and $K$ respectively. When a piece of salt is put in water electrical force acting between sodium and chlorine ions $1cm$ apart is

The law, governing the force between electric charge is known as

Two point charges $Q$ each are placed at a distance $d$ apart. A third point charge $q$ is placed at a distance $x$ from mid-point on the perpendicular bisector. The value of $x$ at which charge $q$ will experience the maximum Coulombs force is :

A particle of $'m'$ and charge $'q'$ is accelerated through a potential difference of $V\;volt,$ its energy will be

For a uniformly charged ring of radius $R,$ the electric field on its axis has the largest magnitude at a distance $h$ from its centre. Then, value of $h$ is

If a unit positive charge is taken from one point to another over an equipotential surface, then

The maximum electric field that a dielectric medium of a capacitor can withstand without break
down (of its insulating property) is called its :

Assertion: In a region, where uniform electric field exists, the net charge within volume of any size is zero.

Reason: The electric flux within any closed surface in region of uniform electric field is zero.

Force acting upon a charged particle kept between the plates of a charged condenser is $F.$ If one plate of the condenser is removed, then the force acting on the same particle will become

A sphere of radius R has a uniform distribution of electric charge (q) in its volume. At a distance x from its centre, the electric field (at $x = \frac{R}{2}$) will be

Statement-I: A charge $q$ is lying at the centre of the line joining two similar charges $Q$ each. The system will be in equilibrium if $q=Q / 4$

Statement-II: For $Q$ to be in equilibrium, sum of the forces on $Q$ due to rest of the two charges must zero.

Charge ${q_2}$ of mass $m$ revolves around a stationary charge ${q_1}$ in a circular orbit of radius $r$ The orbital periodic time of ${q_2}$ would be

Two charges placed in air repel each other by a force of $10^{-4} {~N}$. When oil is introduced between the charges, the force becomes $5 \times 10^{-5} {~N}$. The dielectric constant of oil is

Assertion (A): The basic difference between magnetic lines of force and electric lines of force is electric lines of force are discontinuous and magnetic lines of force are continuous.
Reason (R): Magnetic lines of force exist in a magnet but no electric lines of force exists in a charged body.

The bob of simple pendulum is hanging vertically down from a fixed identical bob by means of string of length $l$. If both bobs are charged with a charge with a charge $q$ each, time period of the pendulum is (ignore the radii of the bobs)

Which of the following is deflected by electric field