1. | \(4\) cm from \(2~\mu\text{C}\). |
2. | \(2\) cm from \(2~\mu\text{C}\). |
3. | \(2\) cm from \(8~\mu\text{C}\). |
4. | \(3\) cm from \(8~\mu\text{C}\). |
The ratio of the electric flux linked with shell \(A\) and shell \(B\) in the diagram shown below is:
1. | \(1: 1\) | 2. | \(1: 2\) |
3. | \(1: 4\) | 4. | \(4: 2\) |
An electric dipole is kept at the origin as shown in the diagram. The point A, B, C are on a circular arc with the centre of curvature at the origin. If the electric fields at A, B and C respectively are , then which of the following is incorrect? \(\left ( d\gg l \right )\)
1.
2.
3.
4.
An electric dipole is placed at the centre of a sphere. Which of the following statements is correct?
1. | The electric flux through the sphere is zero. |
2. | The electric field is zero at every point on the sphere. |
3. | The electric field is zero at every point inside the sphere. |
4. | The electric field is uniform inside the sphere. |
The electric flux from a cube of edge \(l\) is \(\phi\). What will be its value if the edge of the cube is made \(2l\) and the charge enclosed is halved?
1. \(\frac{1}{2}\phi\)
2. \(2\phi\)
3. \(4\phi\)
4. \(\phi\)
A charged particle q of mass m is released on the \(y\text-\)axis at \(y=a\) in an electric field \(\vec E = -4y \hat{j}.\) The speed of particle on reaching the origin will be:
1. \(\sqrt{\frac{2 a}{m q}}\)
2. \(\frac{a}{\sqrt{m q}}\)
3. \(2 a \sqrt{\frac{q}{m}}\)
4. \(2 \sqrt{\frac{a}{m q}}\)
A point charge \(q\) is placed at the center of the open face of a hemispherical surface as shown in the figure. The flux linked with the surface is:
1. zero
2. \(\frac{q}{2\varepsilon_0}\)
3. \(\frac{q}{\varepsilon_0}\)
4. \(q \pi r^2\)
Four charges are arranged at the corners of a square ABCD as shown in the figure. The force on a positive charge kept at the center of the square is:
1. | Zero |
2. | Along diagonal AC |
3. | Along diagonal BD |
4. | Perpendicular to the side AB |
A point charge is placed at the center of the spherical Gaussian surface. The electric flux through the surface is changed if the:
1. | sphere is replaced by a cube of the same volume. |
2. | sphere is replaced by a cube of half volume. |
3. | charge is moved off-centre in the original sphere. |
4. | charge is moved just outside the original sphere. |
An electric dipole is kept in a uniform electric field such that the dipole moment is not collinear with the electric field. It experiences:
1. | a force and torque. |
2. | a force but no torque. |
3. | a torque but no force. |
4. | neither a force nor a torque. |