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.
3.
4.
A charged particle q of mass m is released on the y-axis at y = a in an electric field . The speed of particle on reaching the origin will be:
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. |
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.
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. | \(4: 2\) |
Two charges 2 and 8 are separated by 6 cm. The neutral point is at:
1. | 4 cm from 2 μC. |
2. | 2 cm from 2 μC . |
3. | 2 cm from 8 μC . |
4. | 3 cm from 8 μC . |
The net dipole moment of the system is of the magnitude:
1. q 2a
2. 2q 2a
3. q a
4. 2 (2q 2a)
A spherical conductor of radius 10 cm has a charge of \(3.2 \times 10^{-7}~\mathrm{C}\) distributed uniformly. What is the magnitude of the electric field at a point 15 cm from the center of the sphere?
1. 1.28 x N/C
2. 1.28 x N/C
3. 1.28 x N/C
4. 1.28 x N/C
Two-point charges, +q and –q are held fixed at (–d, 0) and (d, 0) respectively of an (x, y) coordinate system. Then:
1. | E at all points on the y-axis is along . |
2. | The electric field at all points on the x-axis has the same direction. |
3. | Dipole moment is 2qd directed along . |
4. | Work has to be done in bringing a test charge from infinity to the origin. |