Two long current carrying thin wires, both with current $I$, are held by insulating threads of length $L$ and are in equilibrium as shown in the figure, with threads making an angle $'\theta'$ with the vertical. If wires have mass $\lambda$ per unit length then, the value of $I$ is :
( $g =$ gravitational acceleration)
- $2\sin\theta\sqrt{\frac{\pi \lambda gL}{\mu_0 \cos\theta}}$
- $\sin\theta\sqrt{\frac{\pi \lambda gL}{\mu_0 \cos\theta}}$
- $2\sqrt{\frac{\pi gL}{\mu_0}\tan \theta}$
- $\sqrt{\frac{\pi \lambda gL}{\mu_0}\tan \theta}$
The Correct Option is A
Solution and Explanation
Top Questions on Electric Charge
Six point charges are kept \(60^\circ\) apart from each other on the circumference of a circle of radius \( R \) as shown in figure. The net electric field at the center of the circle is ___________. (\( \varepsilon_0 \) is permittivity of free space)
- JEE Main - 2026
- Physics
- Electric Charge
- If the protons and electrons are the only basic charges in the universe, all the observable charges have to be integral multiples of e. Thus, if an object contains x electrons and y protons, the net charge on the object will be
- CUET (UG) - 2025
- Physics
- Electric Charge
- An electric dipole consists of charges \(\pm 4 \mu C\) separated by a distance of \(6\,cm\). Calculate the electric field at a point on the axial line at a distance \(20\,cm\) from its center.
- The force between two point charges separated by a distance \(d\) is \(F\). If one charge is moved away by a distance \(d\), then the new force is:
- KEAM - 2025
- Physics
- Electric Charge
- Two charged particles A and B have charge q each while masses are \(m_1\) & \(m_2\). Both have the same velocity v and enter into a transverse magnetic field B such that their radii are \(r_1\) & \(r_2\). Then the ratio \(m_1 : m_2\) is
- JEE Main - 2024
- Physics
- Electric Charge
Questions Asked in JEE Main exam
In the given figure, the blocks $A$, $B$ and $C$ weigh $4\,\text{kg}$, $6\,\text{kg}$ and $8\,\text{kg}$ respectively. The coefficient of sliding friction between any two surfaces is $0.5$. The force $\vec{F}$ required to slide the block $C$ with constant speed is ___ N.
(Given: $g = 10\,\text{m s}^{-2}$)
- JEE Main - 2026
- Rotational Mechanics
- The reading of the ammeter (\(A\)) in steady state in the following circuit (assuming negligible internal resistance of the ammeter) is ________ A.
- JEE Main - 2026
- Current electricity
- Electric field in a region is given by \[ \vec{E} = A x\,\hat{i} + B y\,\hat{j}, \] where \( A = 10 \,\text{V/m}^2 \) and \( B = 5 \,\text{V/m}^2 \). If the electric potential at a point \( (10, 20) \) is \(500\ \text{V}\), then the electric potential at origin is __________ V.
- JEE Main - 2026
- Electric Potential And Potential Difference
Let $\alpha,\beta\in\mathbb{R}$ be such that the function \[ f(x)= \begin{cases} 2\alpha(x^2-2)+2\beta x, & x<1 \\ (\alpha+3)x+(\alpha-\beta), & x\ge1 \end{cases} \] is differentiable at all $x\in\mathbb{R}$. Then $34(\alpha+\beta)$ is equal to}
- JEE Main - 2026
- Continuity and differentiability
- A conducting rod of mass \( m \) and length \( l \) is moving on an infinite pair of conducting rails as shown. Conducting rails are connected to a resistance \( R \) at one end. Motion is in the vertical plane and horizontal magnetic field in the region is \( B \). Find the terminal speed of the rod.
- JEE Main - 2026
- Electromagnetic induction
Concepts Used:
Electric Charge
What is Electric Charge
It is the property of subatomic particles that experiences a force when put in an electric and magnetic field. It is are of two types: Positive and Negative. It 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.