Two charges q₁ and q₂ are placed 30 cm apart, as shown in the figure. A third charge q₃ is moved along the arc of a circle of radius 40 cm from C to D. The change in the potential energy of the system is $\frac{q_3}{4\pi {\epsilon }_0}k$, where k is:

     

1.	8q2	2.	8q1
3	6q2	4.	6q1

Three capacitors of capacitances 3 μF, 9 μF and 18 μF are connected once in series and another time in parallel. The ratio of equivalent capacitance in the two cases $\left(\frac{{\displaystyle C_s}}{{\displaystyle C_p}}\right)$ will be:

1. 1 : 15

2. 15 : 1

3. 1 : 1

4. 1 : 3

\(\mathrm{A}\), \(\mathrm{B}\) and \(\mathrm{C}\) are three points in a uniform electric field. The electric potential is:

Three charges \(Q\), \(+q \) and \(+q \) are placed at the vertices of an equilateral triangle of side \(l\) as shown in the figure. If the net electrostatic energy of the system is zero, then \(Q\) is equal to:

A cube of a metal is given a positive charge Q. For the above system, which of the following statements is true?

Ten electrons are equally spaced and fixed around a circle of radius R. Relative to V = 0 at infinity, the electrostatic potential V and the electric field E at the centre C are:

What is the potential energy of two equal positive point charges of \(1~ \mu \text{C}\) each held \(1\) m apart in the air?

In the figure the charge Q is at the centre of the circle. Work done by the conservative force is maximum when another charge is taken from point P to:

On rotating a point charge having a charge \(q\) around a charge \(Q\) in a circle of radius \(r\), the work done will be:

In the circuit shown in figure, energy stored in 6 $\mathrm{\mu F}$ capacitor will be: