List of top Physics Questions on Electric Field asked in JEE Main

Consider a circular loop that is uniformly charged and has a radius $ \sqrt{2} $. Find the position along the positive $ z $-axis of the cartesian coordinate system where the electric field is maximum if the ring was assumed to be placed in the $ xy $-plane at the origin:

Two large plane parallel conducting plates are kept 10 cm apart as shown in figure. The potential difference between them is $ V $. The potential difference between the points A and B (shown in the figure) is:

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). 
Assertion (A): Net dipole moment of a polar linear isotropic dielectric substance is not zero even in the absence of an external electric field. Reason
(R): In absence of an external electric field, the different permanent dipoles of a polar dielectric substance are oriented in random directions. 
In the light of the above statements, choose the most appropriate answer from the options given below:

A metallic ring is uniformly charged as shown in the figure. AC and BD are two mutually perpendicular diameters. Electric field due to arc AB to O is ‘E’ magnitude. What would be the magnitude of electric field at ‘O’ due to arc ABC?

An electron is released in the field generated by a non-conductivity sheet of uniform surface charge density $ \sigma $. The rate of change of de-Broglie wavelength associated with the electron varies inversely as the $ n $th power of the distance travelled. Find the value of $ n $.
An electron of mass \( m \) with an initial velocity \( \vec{v} = v_0 \hat{i} (v_0>0) \) enters an electric field \( \vec{E} = -E_0 \hat{k} \). If the initial de Broglie wavelength is \( \lambda_0 \), the value after time \( t \) would be:
\(\sigma\) is the uniform surface charge density of a thin spherical shell of radius \(R\). The electric field at any point on the surface of the spherical shell is:
The distance between charges \(+q\) and \(-q\) is \(2l\) and between \(+2q\) and \(-2q\) is \(4l\). The electrostatic potential at point \(P\) at a distance \(r\) from center \(O\) is \(-\alpha \left[\frac{q}{r^2}\right] \times 10^9 \, \text{V}\), where the value of \(\alpha\) is ______.
(Use \(\frac{1}{4 \pi \epsilon_0} = 9 \times 10^9 \, \text{Nm}^2 \text{C}^{-2}\))
Figure
Graphical variation of electric field due to a uniformly charged insulating solid sphere of radius R, with distance r from the centre O is represented by
uniformly charged insulating solid sphere
A dipole comprises of two charged particles of identical magnitude q and opposite in nature. The mass ‘m’ of the positive charged particle is half of the mass of the negative charged particle. The two charges are separated by a distance ‘l’. If the dipole is placed in a uniform electric field ‘\(\overrightarrow{E}\); such a way that dipole axis makes a very small angle with the electric field, ‘\(\overrightarrow{E}\)'. The angular frequency of the oscillations of the dipole when released is given by.
Two charges each of magnitude 0.01 C and separated by a distance of 0.4 mm constitute an electric dipole. If the dipole is placed in an uniform electric field of 10 dyne/C making 30º angle with \(\overrightarrow E\), the magnitude of torque acting on dipole is:
Given below are two statement: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : If an electric dipole of dipole moment 30 x 10-5 Cm is enclosed by a closed surface, the net flux coming out of the surface will by zero.
Reason R : Electric dipole consists of two equal and opposite charges.
In the light of above, statements, choose the correct answer from the options given below:
In a metallic conductor, under the effect of applied electric field, the free electrons of the conductor 
An electric dipole of dipole moment is 6.0 x 10-6 Cm placed in a uniform electric field of 1.5 x 103 NC-1 in such a way that dipole moment is along electric field. The work done in rotating dipole by 180º in this field will be _____mJ.

The following circuit contains diodes with forward bias having resistance \(25Ω\), and reverse bias having infinite resistance. The ratio of \(\frac{I_{1}}{I_{2}}\) is equal to

 

When electric field is applied to the electrons in a conductor it starts

Two isolated metallic solid spheres of radii $R$ and $2 R$ are charged such that both have same charge density $\sigma$. The spheres are then connected by a thin conducting wire. If the new charge density of the bigger sphere is $\sigma^{\prime}$ The ratio $\frac{\sigma^{\prime}}{\sigma}$ is :

Two uniformly charged spherical conductors, A and B of radii 5 mm and 10 mm are separated by a distance of 2 cm. If the spheres are connected by a conducting wire, then in equilibrium condition, the ratio of the magnitude of the electric fields at surface of the spheres A and B will be
Given below are two statements:
Statement I: A time varying electric field is a source of changing magnetic field and vice-versa. Thus a disturbance in electric or magnetic field creates EM waves.
Statement II: In a material medium, the EM wave travels with speed
\(V=\frac{1}{\sqrt{µ0ε0}}\) In the light of the above statements, choose the correct answer from the options given below.
A velocity selector consists of electric field \(\overrightarrow E=E\hat K\) and magnetic field \(\overrightarrow B=B\hat j\) with \(B = 12 \;mT\). The value of E required for an electron of energy \(728\) \(eV\) moving along the positive x-axis to pass undeflected is (Given, mass of electron = \(9.1 × 10^{–31}\) kg)
A spherically symmetric charge distribution is considered with charge density varying as
\(ρ(r) =   \begin{cases}     ρ_0(\frac 34−\frac rR)      &; \text{for} \ r≤R\\     Zero  &; \text{for}\ r>R    \end{cases}\)
Where, r(r<R) is the distance from the centre O (as shown in figure) The electric field at point P will be :
A spherically symmetric charge distribution
If the potential barrier across a p–n junction is 0.6 V. Then the electric field intensity, in the depletion region having the width of 6×10–6 m, will be ______× 105 N/C.
 A vertical electric field of magnitude 4.9 × 105 N/C just prevents a water droplet of a mass of 0.1 g from falling. The value charge on the droplet will be(Given g = 9.8 m/s2)
Two point charges A and B of magnitude \(+8 \times 10^{–6} C\) and \(-8 \times 10^{–6} C\) respectively are placed at a distance d apart. The electric field at the middle point O between the charges is \(6.4 \times 10^{4} NC^{–1}\). The distance ‘d’ between the point charges A and B is:
An electron with kinetic energy $K_1$ enters between parallel plates of a capacitor at an angle '$\alpha$' with the plates. It leaves the plates at angle '$\beta$' with kinetic energy $K_2$. Then the ratio of kinetic energies $K_1 : K_2$ will be: