Q. No.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 \(q\) 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. \(q \pi r^2\)
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 the 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. \(2 \sqrt{\frac{a}{m q}}\)
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. |
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 \(\vec E_1,\vec E_2,\vec E_3,\) then which of the following is incorrect? \(\left ( d\gg l \right )\)
1. \(\vec E_1=-\vec E_3\)
2. \(\vec E_1=-2\vec E_2\)
3. \(\vec E_1=\vec E_3\)
4. \(\vec E_3=-2\vec E_2\)
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. | \(4: 2\) |
| 1. | \(4~\text{cm}\) from \(2~\mu\text{C}.\) |
| 2. | \(2~\text{cm}\) from \(2~\mu\text{C}.\) |
| 3. | \(2~\text{cm}\) from \(8~\mu\text{C}.\) |
| 4. | \(3~\text{cm}\) from \(8~\mu\text{C}.\) |
The net dipole moment of the system is of the magnitude:
1. \(q\times 2a\)
2. \(2q \times 2a\)
3. \(q\times a\)
4. \(2\times (2q\times 2a)\)
A spherical conductor of radius \(10~\text{cm}\) has a charge of \(3.2 \times 10^{-7}~\text{C}\) distributed uniformly. What is the magnitude of the electric field at a point \(15~\text{cm}\) from the centre of the sphere?
\(\left(\frac{1}{4\pi \varepsilon _0} = 9\times 10^9~\text{N-m}^2/\text{C}^2\right)\)
1. \(1.28\times 10^{5}~\text{N/C}\)
2. \(1.28\times 10^{6}~\text{N/C}\)
3. \(1.28\times 10^{7}~\text{N/C}\)
4. \(1.28\times 10^{4}~\text{N/C}\)
| 1. | \(E\) at all points on the \(y\text-\)axis is along \(\hat i.\) |
| 2. | The electric field \(\vec E\) at all points on the \(x\text-\)axis has the same direction. |
| 3. | Dipole moment is \(2qd\) directed along \(\hat i.\) |
| 4. | Work has to be done in bringing a test charge from infinity to the origin. |
© 2025 GoodEd Technologies Pvt. Ltd.