A charge q is to be divided on two small conducting spheres. What should be the value of charges on the spheres so that when placed at a certain distance apart, the repulsion force between them is maximum

(1) $\frac{q}{4} and \frac{3q}{4}$

(2) $\frac{q}{2} and \frac{q}{2}$

(3) $\frac{q}{3} and \frac{q}{3}$

(4) $\frac{q}{4} and \frac{q}{4}$

If a soap bubble is given some charge, then its radius

(1) Increases

(2) Decreases

(3) Remain unchanged

(4) May increase or decrease depending upon the give charge is positive or negative

The law, governing the force between electric charges is known as 

(1) Ampere's law

(2) Ohm's law

(3) Faraday's law

(4) Coulomb's law

F_g and F_e represents gravitational and electrostatic force respectively between electrons situated at a distance 10 cm. The ratio of F_g/ F_e is of the order of 

(1) 10⁴²

(2) 10

(3) 1

(4) 10^–43

A soap bubble is given a negative charge, then its radius 

(1) Decreases

(2) Increases

(3) Remains unchanged

(4) Nothing can be predicted as information is insufficient

Four charges are arranged at the corners of a square ABCD, as shown in the adjoining figure. The force on the charge kept at the centre O is 

(1) Zero

(2) Along the diagonal AC

(3) Along the diagonal BD

(4) Perpendicular to side AB

A total charge Q is broken in two parts Q₁ and Q₂ 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) $Q_2=\frac{Q}{4},Q_1=Q-\frac{2Q}{3}$

(3) $Q_2=\frac{Q}{4},Q_1=\frac{3Q}{4}$

(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 = 

(1) – q

(2) –2q

(3) $-\frac{q}{2}$

(4) 4q

Two small spheres each having the charge +Q are suspended by insulating threads of length L from a hook. 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) ${180}^o,\frac{1}{4\pi {\epsilon }_0}\frac{Q^2}{L^2}$