A total charge \(Q\) is broken in two parts \(Q_1\) and \(Q_2\) and they are placed at a distance \(R\) from each other. The maximum force of repulsion between them will occur, when:

Two charges \(+2\) C and \(+6\) C are repelling each other with a force of \(12\) N. If each charge is given \(-2\) C of charge, then the value of the force will be:

Two charges 2 $\mathrm{\mu C}$ and 8 $\mathrm{\mu C}$ are separated by 6 cm. The neutral point is at:

Two positive ions, each carrying a charge q, are separated by a distance d. If F is the force of repulsion between the ions, the number of electrons missing from each ion will be:
(e is the charge on an electron)

1. $\frac{4\pi {\epsilon }_{0}F{d}^2}{e^2}$

2. $\sqrt{\frac{4\pi {\epsilon }_{0}F{d}^2}{d^2}}$

3. $\sqrt{\frac{4\pi {\epsilon }_{0}F{d}^2}{e^2}}$

4. $\frac{4\pi {\epsilon }_{0}F{d}^2}{q^2}$

The acceleration of an electron due to the mutual attraction between the electron and a proton when they are \(1.6~\mathring{A}\) apart is:
( \(\frac{1}{4 \pi \varepsilon_0}=9 \times 10^9~ \text{Nm}^2 \text{C}^{-2}\) )

Two point charges \(A\) and \(B\), having charges \(+Q\) and \(-Q\) respectively, are placed at a certain distance apart and the force acting between them is \(F.\) If \(25\%\) charge of \(A\) is transferred to \(B\), then the force between the charges becomes:

The unit of permittivity of free space ε₀ is:

Two small spheres each having the charge +Q are suspended by insulating threads of length L from a hook. If this arrangement is taken in space where there is no gravitational effect, then the angle between the two suspensions and the tension in each will be:

1. ${180}^o,$ $\frac{1}{4\pi {\epsilon }_0}\frac{Q^2}{{\left(2L\right)}^2}$

2. ${90}^o,$ $\frac{1}{4\pi {\epsilon }_0}\frac{Q^2}{L^2}$

3. ${180}^o,$ $\frac{1}{4\pi {\epsilon }_0}\frac{Q^2}{2L^2}$

4. ${180}^o,$ $\frac{1}{4\pi {\epsilon }_0}\frac{Q^2}{L^2}$ 

Four charges are arranged at the corners of a square ABCD as shown in the figure. The force on a positive charge kept at the center of the square is: