Which of the following processes involves the principle of electrostatic induction?

1. Pollination

2. Chocolate making

3. Xerox copying

4. All of these

When a conducting soap bubble is negatively charged then:

1. Its size starts varying arbitrarily

2. It expands

3. It contracts

4. No change in its size takes place

Coulomb's law is analogous to:

1. Charge conservation law

2. Newton's second law of motion

3. Law of conservation of energy

4. Newton's law of gravitation

Two-point charges Q₁ and Q₂ exert a force F on each other when kept at a certain distance apart. If the charge on each particle is halved and the distance between the two particles is doubled, then the new force between the two particles would be:

1. $\frac{\mathrm{F}}{2}$

2. $\frac{\mathrm{F}}{4}$

3. $\frac{\mathrm{F}}{8}$

4. $\frac{\mathrm{F}}{16}$

Two equally charged identical small balls kept at some fixed distance apart exert a repulsive force F on each other. A similar uncharged ball, after touching one of them is placed at the mid-point of the line joining the two balls. The force experienced by the third ball is: 

1. 4F

2. 2F

3. F

4. $\frac{\mathrm{F}}{16}$

Two equal point charges A and B are R distance apart. A third point charge placed on the perpendicular bisector at a distance d from the centre will experience a maximum electrostatic force when:

1. $\mathrm{d}=\frac{\mathrm{R}}{2\sqrt{2}}$

2. $\mathrm{d}=\frac{\mathrm{R}}{\sqrt{2}}$

3. $\mathrm{d}=\mathrm{R}\sqrt{2}$

4. $\mathrm{R}=2\sqrt{2}\mathrm{R}$

A charged gold leaf electroscope has its leaves apart by a certain amount of having enclosed air. When the electroscope is subjected to X-rays, then the leaves:

1. Further dilate

2. Start oscillating

3. Collapse

4. Remain unaltered

Two equal positive charges Q are fixed at points (a, 0) and (-a, 0) on the x-axis. An opposite charge -q at rest is released from point (0, a) on the y-axis. The charge -q will

1. move to infinity.

2. move to the origin and rest there.

3. undergo SHM about the origin.

4. execute oscillatory periodic motion but not SHM.

Four charges each equal to Q are placed at the four corners of a square and a charge q is placed at the centre of the square. If the system is in equilibrium then the value of q is:

1. $\frac{\mathrm{Q}}{2}(1+2\sqrt{2})$

2. $\frac{-\mathrm{Q}}{4}(1+2\sqrt{2})$

3. $\frac{\mathrm{Q}}{4}(1+2\sqrt{2})$

4. $\frac{-\mathrm{Q}}{2}(1+2\sqrt{2})$

According to Coulomb's Law, which is the correct relation for the following diagram?

1. ${\mathrm{q}}_1{\mathrm{q}}_2<0$

2. ${\mathrm{q}}_1{\mathrm{q}}_2>0$

3. ${\mathrm{q}}_1{\mathrm{q}}_2=0$

4. ${\mathrm{q}}_1{\mathrm{q}}_2>>100\mathrm{C}$