Two nonconducting plates A and B of radii 2R and 4R, respectively, are kept at distances x and 2x from the point charge q. A surface cutout of a nonconducting shell C is kept such that its center coincides with the point charge. Each plate and spherical surface carries surface charge density $\sigma$.

If F_A, F_B, and F_C are the forces on plate A, plate B, and spherical surface C due to charge q, respectively, then

• A

  $F_{\mathit{A}}\mathit{=}{F}_{\mathit{B}}\mathit{=}{F}_{\mathit{C}}$

• B

  $F_C<F_B<F_A$

• C

  $F_C>F_B>F_A$

• D

  $F_A=F_B>F_C$

If ${\varphi }_1$ is flux through surface of (B) due to electric field of (A) and ${\varphi }_2$ is the flux through (A) due to electric field of (B), then

• A

  ${\varphi }_1={\varphi }_2$

• B

  ${\varphi }_1>{\varphi }_2$

• C

  ${\varphi }_1<{\varphi }_2$

• D

  $\mathrm{It} \mathrm{depends} \mathrm{on} \mathrm{r} \mathrm{and} \mathrm{R}$

If distance x and radius R are doubled so that F_A becomes ${\mathrm{F}}_{\mathrm{A}}^{\mathrm{\prime }}$, F_B becomes ${\mathrm{F}}_{\mathrm{B}}^{\mathrm{\prime }}$, then the correct option is

• A

  ${\mathrm{F}}_{\mathrm{B}}>{\mathrm{F}}_{\mathrm{B}}^{\mathrm{\prime }}$

• B

  ${\mathrm{F}}_{\mathrm{B}}^{\mathrm{\prime }}>{\mathrm{F}}_{\mathrm{B}}$

• C

  ${\mathrm{F}}_{\mathrm{A}}^{\mathrm{\prime }}>{\mathrm{F}}_{\mathrm{B}}^{\mathrm{\prime }}$

• D

  none of these

Submit Answer