MCQ
A solid conducting sphere of radius $R_1$ is surrounded by another concentric hollow conducting sphere of radius $R_2$. The capacitance of this assembly is proportional to
  • A
    $\frac{{{R_2} - {R_1}}}{{{R_1}{R_2}}}$
  • B
    $\frac{{{R_2} + {R_1}}}{{{R_1}{R_2}}}$
  • C
    $\frac{{{R_1}{R_2}}}{{{R_1} + {R_2}}}$
  • $\frac{{{R_1}{R_2}}}{{{R_2} - {R_1}}}$

Answer

Correct option: D.
$\frac{{{R_1}{R_2}}}{{{R_2} - {R_1}}}$
d
(d) Capacitance of the given assembly

$C = 4\pi {\varepsilon _0}\,\left( {\frac{{{R_1}{R_2}}}{{{R_2} - {R_1}}}} \right)$ 

==>$ C \propto \frac{{{R_1}{R_2}}}{{({R_2} - {R_1})}}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Light of wavelength $6000\,\mathring A$ is incident on a slit of width $0.30\,mm$ . The screen is placed $2\,m$ from slit. Find position of the first minima
One mole of an ideal gas at an initial temperature of $T\, K$ does $6 R$ joules of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant volume is $5/3$, the final temperature of gas will be
A charged particle of charge $Q $ is held fixed and another charged particle of mass $m$ and charge $q$ (of the same sign) is released from a distance $r.$ The impulse of the force exerted by the external agent on the fixed charge by the time distance between $Q$ and $q$ becomes $2r$ is
The fine powder of a coloured glass is seen as
Consider two solid spheres of radii $\mathrm{R}_{1}=1 \;\mathrm{m}$ $\mathrm{R}_{2}=2\; \mathrm{m}$ and masses $\mathrm{M}_{1}$ and $\mathrm{M}_{2},$ respectively. The gravitational field due to sphere $(1)$ and $(2)$ are shown. The value of $\frac{\mathrm{M}_{1}}{\mathrm{M}_{2}}$ is
A disc of radius $r$ and carrying positive charge $q$ is rotating with an angular speed $l$ in a uniform magnetic field $B$ about a fixed axis as shown in figure, such that angle made by axis of disc with magnetic field is $\theta $. Torque applied by axis on the disc is 
Balls $A$ and $B$ are thrown from two points lying on the same horizontal plane separated by a distance $120\,m$. Which of the following statement$(s)$ is/are correct.
A thin uniform stick of length $l$ and mass $m$ is held horizontally with its end $B$ hinged on the edge of a table. Point $A$ is suddenly released. The acceleration of the centre of mass of the stick at the time of release, is
At what temperature (in $ ^{\circ} C$) a gold ring of diameter $6.230$ $cm$ be heated so that it can be fitted on a wooden bangle of diameter $6.241 \,cm$ ? Both the diameters have been measured at room temperature $\left(27^{\circ} C \right)$. (Given: coefficient of linear thermal expansion of gold $\alpha_{L}=1.4 \times 10^{-5} \,K ^{-1}$ )
While measuring the speed of sound by performing a resonance column experiment, a student gets the first resonance condition at a column length of $18\ cm$ during winter. Repeating the same experiment during summer, she measures the column length to be $x\ cm$ for the second resonance. Then