Two pith balls carrying equal charges are suspended from a common point by strings of equal length. The equilibrium separation between them is r . Now - Physics MCQ Physics | ExamTest.live

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Two pith balls carrying equal charges are suspended from a common point by strings of equal length. The equilibrium separation between them is r . Now the strings are rigidly clamped at half the height (y /2). The equilibrium separation between the balls now becomes:

A $(\frac{r}{2})^{1/2}$
B $(\frac{r}{3 2})$
C $\frac{2 r}{3}$
D $\frac{r}{3 2}$

Solution & Step-by-step Explanation

In equilibrium: tan θ = \frac{F _{e}}{m g} = \frac{k q ^{2}}{r ^{2} m g} .Also, from geometry tan θ = \frac{r /2}{y} .So, \frac{r}{2 y} = \frac{k q ^{2}}{r ^{2} m g} ⟹ y \propto r^{3} .When height is y /2 : \frac{y}{y /2} = \frac{r ^{3}}{( r ^{'} ) ^{3}} 2 = \frac{r ^{3}}{( r ^{'} ) ^{3}} ⟹ (r^{'})^{3} = \frac{r ^{3}}{2} r^{'} = \frac{r}{3 2}

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Two pith balls carrying equal charges are suspended from a common point by strings of equal length. The equilibrium separation between them is r . Now the strings are rigidly clamped at half the height (y /2). The equilibrium separation between the balls now becomes:

(\frac{r}{2})^{1/2}

(\frac{r}{3 2})

\frac{2 r}{3}

\frac{r}{3 2}

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Two pith balls carrying equal charges are suspended from a common point by strings of equal length. The equilibrium separation between them is $r$ . Now the strings are rigidly clamped at half the height ( $y /2$ ). The equilibrium separation between the balls now becomes:

Solution & Step-by-step Explanation

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Two pith balls carrying equal charges are suspended from a common point by strings of equal length. The equilibrium separation between them is r. Now the strings are rigidly clamped at half the height (y/2). The equilibrium separation between the balls now becomes:

Solution & Step-by-step Explanation

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Ready for a Full Test?

Discussion

Two pith balls carrying equal charges are suspended from a common point by strings of equal length. The equilibrium separation between them is $r$ . Now the strings are rigidly clamped at half the height ( $y /2$ ). The equilibrium separation between the balls now becomes: