Two pith balls carrying equal charges are suspended from a common point by strings of equal length, the equilibrium separation between them is $$r$$ (as shown in Fig. I). Now, as shown in Fig. II, the strings are rigidly clamped at half the height. The equilibrium separation between the balls now becomes:

1. $$\frac{r}{\sqrt[3]{2}}$$
2. $$\frac{r}{\sqrt[2]{2}}$$
3. $$\frac{2r}{3}$$
4. none of the above

Subtopic:  Coulomb's Law |
70%
From NCERT
AIPMT - 2013
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
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To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A charge $$q$$ is placed at the center of the line joining two equal charges $$Q.$$ The system of the three charges will be in equilibrium if $$q$$ is equal to:
1. $$-Q/4$$
2. $$Q/4$$
3. $$-Q/2$$
4. $$Q/2$$
Subtopic:  Coulomb's Law |
67%
From NCERT
NEET - 2013
Hints

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

Subtopic:  Coulomb's Law |
77%
From NCERT
AIPMT - 2010
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints