Electric field due to point charges, electric field lines, electric dipole and field due to a dipole - One Line Questions
1.
What is the dimensionality of the electric dipole moment? —
[M^0 L^1 T^1 A^1]
2.
An electric dipole is placed in a uniform electric field E. The potential energy of the dipole is given by U = -pE cos(theta), where p is the dipole moment and theta is the angle between p and E. The dipole is in stable equilibrium when theta is: —
0 degrees
3.
The electric field at a point P, which is very far from a dipole, is proportional to (1/r^n). What is the value of n? —
3
4.
The magnitude of the electric field due to a point charge q at a distance r is proportional to: —
1/r^2
5.
The electric field at a point located far away from an electric dipole along its axis is proportional to: —
1/r^3
6.
For a dipole, the electric field on the perpendicular bisector at a distance r from the center is proportional to: —
1/r^3
7.
If a point charge +q is placed at the origin, the electric field at point (x, y, z) is proportional to: —
1/r^2
8.
The electric field due to a dipole at a point on its axis is directed: —
Along the dipole axis, away from the center
9.
The electric field due to a system of two equal and opposite charges (a dipole) at a point far away on the equatorial line is directed: —
Parallel to the dipole axis, opposite to the direction of the dipole moment
10.
An electric dipole is placed in a uniform external electric field. The net force on the dipole is: —
Always zero
11.
The electric field at a point P due to a dipole is zero if P is: —
At the center of the dipole
12.
The electric field lines for a system of two equal positive charges are: —
Diverging from the midpoint
13.
The electric field lines for two identical positive charges are best described as: —
Diverging outwards from a region between them
14.
What is the unit of electric dipole moment? —
Coulomb-meter (C·m)
15.
Electric field lines are imaginary and are used to visualize the electric field. They provide information about: —
Both direction and magnitude
16.
The electric field at a point due to an electric dipole is proportional to the product of the dipole moment and the: —
Cube of the distance from the dipole
17.
In a uniform electric field, the electric field lines are: —
Parallel and equally spaced
18.
The electric field strength at a distance r from a point charge of magnitude Q is given by E = kQ/r^2. If the charge is -Q, the electric field at the same distance is: —
-E
19.
The electric field at a distance r from a point charge Q is given by E = kQ/r^2. If Q is doubled and r is halved, the new electric field will be: —
8E
20.
The electric field lines never form closed loops in electrostatics because: —
Electric field is always conservative
21.
Electric field lines never intersect because: —
It would imply two directions of the electric field at the same point
22.
The number of electric field lines passing through a surface is proportional to the: —
Charge enclosed by the surface
23.
What is the work done in moving a charge from one point to another in an electric field? —
Equal to the change in potential energy
24.
What is the net charge of an electric dipole? —
Zero
25.
If the distance from a point charge is doubled, the electric field strength at that point becomes: —
One-fourth
26.
If the medium is changed from vacuum to a dielectric medium with dielectric constant K, the electric field due to a point charge: —
Decreases by a factor of K
27.
Consider a dipole with charges +q and -q separated by 2a. The electric field at a distance r >> a along the axis is approximately: —
k(2qa)/(r^3)
28.
The electric field strength at the center of an electric dipole is: —
Minimum (zero)
29.
An electric dipole is placed in a non-uniform electric field. It will experience: —
Both a net force and a torque
30.
Electric field lines originate from positive charges and terminate on: —
Negative charges
31.
The electric field at a very large distance from an electric dipole is proportional to: —
p/r^3
32.
The electric field lines are perpendicular to the surface of a: —
Conductor in electrostatic equilibrium
33.
The direction of the electric dipole moment vector is from: —
Negative charge to positive charge
34.
The electric field at a point is defined as the force per unit: —
Positive test charge
35.
If the distance between two charges of an electric dipole is '2a' and the charge is 'q', the dipole moment is: —
2aq
36.
Gauss's Law is a consequence of the inverse square law for the electrostatic force. The electric field due to a point charge follows an inverse square law, meaning it is proportional to: —
1/r^2
37.
The electric field lines due to a negative point charge are: —
Radial and inwards
38.
The electric field lines of a dipole are: —
Curved lines starting from the positive charge and ending on the negative charge
39.
The density of electric field lines represents: —
The magnitude of the electric field
40.
For an electric dipole, the electric field strength is maximum along: —
The axis
41.
What is the electric dipole moment? —
The product of the charge and the distance between them
42.
The electric field at a point is zero. This implies that: —
The net force on a test charge at that point is zero
43.
Which of the following statements about electric field lines is incorrect? —
They intersect each other at points where the field is zero.
44.
Which quantity is conserved for an isolated system of charges? —
Total charge
45.
What is the direction of the electric field at a point due to a positive point charge? —
Away from the charge
46.
An electric dipole consists of: —
Two equal and opposite charges separated by a small distance
47.
What is the SI unit of electric field? —
Volt per meter (V/m)
48.
The unit of electric field, Newton per Coulomb (N/C), is equivalent to: —
Volt per meter (V/m)
49.
The electric field lines are closer where the electric field is: —
Stronger