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:

1.	\(Q_2=\frac{Q}{R}, Q_1=Q-\frac{Q}{R}\)
2.	\(Q_2=\frac{Q}{4}, Q_1=Q-\frac{2 Q}{3}\)
3.	\(Q_2=\frac{Q}{4}, Q_1=\frac{3 Q}{4}\)
4.	\(Q_1=\frac{Q}{2}, Q_2=\frac{Q}{2}\)

Three charges \(4q,Q,\) and \(q\) are in a straight line in the position of \(0,l/2,\) and \(l\) respectively. The resultant force on \(q\) will be zero if \(Q\) equal to:
1. \(-q\)
2. \(-2q\)
3. \(\frac{-q}{2}\)
4. \(4q\)

Two charges each of 1 coulomb are at a distance 1 km apart, the force between them is 

(1) 9 × 10³ Newton

(2) 9 × 10^–3 Newton

(3) 1.1 × 10^–4 Newton

(4) 10⁴ Newton

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 equally charged, identical metal spheres A and B repel each other with a force 'F'. The spheres are kept fixed with a distance 'r' between them. A third identical, but uncharged sphere C is brought in contact with A and then placed at the mid-point of the line joining A and B. The magnitude of the net electric force on C is 

(1) F

(2) 3F/4

(3) F/2

(4) F/4

The magnitude of electric field intensity E is such that, an electron placed in it would experience an electrical force equal to its weight is given by 

(1) mge

(2) $\frac{mg}{e}$

(3) $\frac{e}{mg}$

(4) $\frac{e^2}{m^2}g$

An uncharged sphere of metal is placed in between two charged plates as shown. The lines of force look like 

(1) A

(2) B

(3) C

(4) D

The figures below show regular hexagons, with charges at the vertices. In which of the following cases the electric field at the centre is not zero?

(1) 1

(2) 2

(3) 3

(4) 4

An electric charge q is placed at the centre of a cube of side a. The electric flux on one of its faces will be:

(1) $\frac{q}{6{\epsilon }_0}$

(2) $\frac{q}{{\epsilon }_0{a}^2}$

(3) $\frac{q}{4\pi {\epsilon }_0{a}^2}$

(4) $\frac{q}{{\epsilon }_0}$