A positive charge $Q$ is situated at the centre of a cube. The electric flux through any face of the cube is (in $SI$ units)
- $\frac{Q}{6\varepsilon_{0}}$
- $4\pi Q$
- $\frac{Q}{4\pi\varepsilon_{0}}$
- $\frac{Q}{6\pi\varepsilon_{0}}$
The Correct Option is A
Solution and Explanation
According to Gauss theorem, the flux from any closed surface
$\phi_E = \frac{Q}{\varepsilon_0}$
Cube has $6$ faces, so electric flux from any face $\phi_E = \frac{Q}{6\varepsilon_0}$
Top Questions on Electric charges and fields
- Derive the expression for Electric Field Intensity on the axial and equatorial line of a dipole.
- HBSE Class 12 - 2026
- Physics
- Electric charges and fields
- State Gauss’s Theorem and use it to find the electric field due to an infinitely long charged wire or a thin spherical shell.
- HBSE Class 12 - 2026
- Physics
- Electric charges and fields
- A charge of 2 $\mu C$ is placed in an electric field of intensity \( 4 \times 10^3 \, \text{N/C} \). What is the force experienced by the charge?
- MHT CET - 2025
- Physics
- Electric charges and fields
- When three particles each having a positive charge $q$ are placed at the three vertices of an equilateral triangle, then the electrostatic force between any two particles is $F$. If a fourth particle of charge $3q$ is placed at the midpoint of one of the sides of the triangle, then the net electrostatic force on the fourth particle due to the remaining three particles is
- TS EAMCET - 2025
- Physics
- Electric charges and fields
- A proton and an alpha particle enter a uniform electric field perpendicular to the direction of the field. The ratio of distances travelled by the proton and the alpha particle in the direction of the field after a time of $t$ seconds is:
- TS EAMCET - 2025
- Physics
- Electric charges and fields
Questions Asked in WBJEE exam
What are the charges stored in the \( 1\,\mu\text{F} \) and \( 2\,\mu\text{F} \) capacitors in the circuit once current becomes steady?
- WBJEE - 2026
- Capacitors and Capacitance
Which one among the following compounds will most readily be dehydrated under acidic condition?
- WBJEE - 2026
- Organic Reactions
Manufacturers supply a zener diode with zener voltage \( V_z=5.6\,\text{V} \) and maximum power dissipation \( P_{\max}=\frac14\,\text{W} \). This zener diode is used in the circuit shown. Calculate the minimum value of the resistance \( R_s \) so that the zener diode will not burn when the input voltage is \( V_{in}=10\,\text{V} \).
- WBJEE - 2026
- Zener Diodes
Two charges \( +q \) and \( -q \) are placed at points \( A \) and \( B \) respectively which are at a distance \( 2L \) apart. \( C \) is the midpoint of \( AB \). The work done in moving a charge \( +Q \) along the semicircle CSD (\( W_1 \)) and along the line CBD (\( W_2 \)) are
- WBJEE - 2026
- electrostatic potential and capacitance
A piece of granite floats at the interface of mercury and water. If the densities of granite, water and mercury are \( \rho, \rho_1, \rho_2 \) respectively, the ratio of volume of granite in water to that in mercury is
- WBJEE - 2026
- Buoyancy and Floatation
Concepts Used:
Electric charges and field
What is Electric Charge
It is the property of subatomic particles that experiences a force when put in an electric and magnetic field.
What is Electric Field
It is a property associated with each point in space when charge is present in any form. The magnitude and direction of the electric field are expressed by E, called electric field strength or electric field intensity.
Electric charges are of two types: Positive and Negative. It is commonly carried by charge carriers protons and electrons.
Properties of Electric Charge
Various properties of charge include the following :-
- Additivity of Electric Charge
- Conservation of Electric Charge
- Quantization of Electric Charge
Types of electric charge
Two kinds of electric charges are there :-
Negative Charge - When an object has a negative charge it means that it has more electrons than protons.
Positive Charge - When an object has a positive charge it means that it has more protons than electrons.
When there is an identical number of positive and negative charges, the negative and positive charges would cancel out each other and the object would become neutral.