1. | \(2E\) | 2. | \(\Large\frac{3E}{2}\) |
3. | \(\Large\frac{4E}{3}\) | 4. | \(\Large\frac{5E}{4}\) |
Assertion (A): | The electrostatic field of a charge distributed uniformly over the surface of a sphere vanishes within the sphere, only at its centre. |
Reason (R): | This cancellation occurs at the centre due to the symmetry of the sphere and the symmetric, uniform charge distribution. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |
1. | I, III | 2. | II |
3. | I, II, III | 4. | none of I, II, III |
\(\mathrm{(A)}\) | A positive point charge \(q\) is placed at the centre of an uncharged conducting sphere. Electric field is measured outside the sphere, as a function of the distance \((r)\) from the centre.![]() |
\(\mathrm{(I)}\) | \(E=0\) |
\(\mathrm{(B)}\) | A positive point charge \(q\) is placed within an uncharged conducting sphere, but not at its centre. Electric field is measured outside the sphere, as a function of distance \((r)\) from centre \((O).\)![]() |
\(\mathrm{(II)}\) | \(E={\Large\frac{kq}{r^2}}\) |
\(\mathrm{(C)}\) | A pair of point charges \((+q,-q)\) are placed within an uncharged conducting sphere, symmetrically about its centre \((O).\) ![]() |
\(\mathrm{(III)}\) | \(E<{\Large\frac{kq}{r^2}}\) |
\(\mathrm{(D)}\) | A positive point charge \(q\) is placed outside a spherical conductor, with the centre \(O.\)![]() |
\(\mathrm{(IV)}\) | \(E>{\Large\frac{kq}{r^2}}\) |
1. | \(\mathrm{A \text- I, B\text- I, C\text- III, D\text- IV}\) | 2. | \(\mathrm{A\text- II, B \text- IV, C \text- III, D \text- II}\) |
3. | \(\mathrm{A \text- II, B \text- II, C\text - I, D \text- III}\) | 4. | \(\mathrm{A \text- I, B \text- IV, C \text- I, D \text- IV}\) |
1. | \(\dfrac{2}{9}\) | 2. | \(\dfrac{4}{9}\) |
3. | \(\dfrac{9}{2}\) | 4. | \(\dfrac{9}{4}\) |
1. | constant | 2. | proportional to \(\dfrac{1}{r}\) |
3. | \(\dfrac{1}{r^2}\) | proportional to4. | \(\dfrac{1}{r^3}\) | proportional to
1. | remains constant in magnitude and direction. |
2. | increases in magnitude, but retains its direction. |
3. | decreases in magnitude, but retains its direction. |
4. | changes in magnitude and direction. |
1. | \(|\vec E_m|=\left|\dfrac{\vec E_Q}{K}\right|,\) and the two fields are in opposite directions. |
2. | \(|\vec E_Q|=\left|\dfrac{\vec E_m}{K}\right|,\) and the two fields are in the same direction. |
3. | \(|\vec E_Q+\vec E_m|=\left|\dfrac{\vec E_Q}{K}\right|,\) and the two fields are in opposite directions. |
4. | \(|\vec E_Q+\vec E_m|=\left|\dfrac{\vec E_m}{K}\right|,\) and the two fields are in the same direction. |
1. | \({\dfrac{q\lambda}{4\pi\varepsilon_0}}\) | 2. | \({\dfrac{q\lambda}{2\pi\varepsilon_0}}\) |
3. | \({\dfrac{2q\lambda}{\pi\varepsilon_0}}\) | 4. | \({\dfrac{q\lambda}{8\pi\varepsilon_0}}\) |