Electric potential and equipotential surfaces - One Line Questions
1.
What is the potential difference between two points if 10 Joules of work is done to move a charge of 5 Coulombs between them? —
2 Volts
2.
If the electric potential is given by V = A/r, then the electric field E is proportional to: —
1/r^2
3.
The electric potential due to an electric dipole at a point on its axis at a distance r from the center is proportional to: —
1/r^2
4.
The electric potential at a distance r from a uniformly charged infinite rod is proportional to: —
1/r
5.
Consider two points A and B in an electric field. If V_A - V_B = 5V, and a charge of +2C is moved from A to B, the work done by the electric field is: —
-10 J
6.
Work done in moving a charge of -2 C from infinity to a point where the potential is 5V is: —
-10 J
7.
If E = 2x^2 i + 3y^2 j + 4z^2 k, then the potential difference between the origin (0,0,0) and the point (1,1,1) is: —
10/3 V
8.
The potential difference between two points is 100V. If a charge of 1 microcoulomb is moved between these points, the work done is: —
10^-4 Joules
9.
What is the potential difference between two points separated by a distance of 1 meter in a uniform electric field of 100 N/C, if the displacement is along the field lines? —
100 V
10.
What is the potential at the center of a square of side 'a' with charges q at each corner? —
2kq/a
11.
If the electric potential V is given by V = 6x - 8xy^2 + 2yz^2, what is the electric field at the origin (0,0,0)? —
6i - 8j + 0k
12.
What is the electric potential at infinity for a system of charges? —
Always zero
13.
For a dipole, the potential is zero on the: —
Perpendicular bisector
14.
Which of the following is NOT an equipotential surface for a uniformly charged infinite line? —
Planes perpendicular to the line
15.
The equipotential surfaces corresponding to a dipole are: —
Complex shapes, not easily described
16.
What is the nature of equipotential surfaces for an isolated positive point charge? —
Concentric spheres centered on the charge
17.
An equipotential surface is a surface over which the electric potential is: —
Constant
18.
If V is the electric potential and E is the electric field, which relation is correct? —
E = -grad(V)
19.
Which statement is INCORRECT about equipotential surfaces? —
Equipotential surfaces can intersect each other.
20.
For a system of charges, the principle of superposition applies to: —
Both electric field and electric potential
21.
If a positive charge is moved from a region of low potential to a region of high potential, its potential energy: —
Increases
22.
Electric potential is a scalar quantity. What does this imply? —
It only has magnitude.
23.
If the electric field is zero in a region, what can be said about the electric potential in that region? —
It must be constant.
24.
The potential energy of a system of two charges q1 and q2 separated by a distance r is given by: —
k * q1 * q2 / r
25.
Which of the following represents the potential energy of a system of two point charges q1 and q2 separated by distance r? —
k * q1 * q2 / r
26.
What is the potential difference between the center and the surface of a uniformly charged solid insulating sphere of radius R and charge Q? —
KQ/(2R)
27.
What is the potential at the center of a uniformly charged ring of radius R and total charge Q? —
KQ/R
28.
What is the electric potential at the center of a uniformly charged solid insulating sphere of radius R and charge Q? —
3KQ/(2R)
29.
Work done in moving a charge between two points on the same equipotential surface is: —
Zero
30.
For a single point charge, the equipotential surfaces are: —
Concentric spheres
31.
Electric field lines originate from positive charges and terminate on negative charges. Equipotential surfaces are: —
Perpendicular to electric field lines.
32.
What is the electric potential at a distance r from a point charge Q in vacuum? —
Q / (4 * pi * epsilon_0 * r)
33.
If the potential energy of a charge q at a point is U, the electric potential at that point is: —
U/q
34.
In a region of uniform electric field, equipotential surfaces are: —
Parallel planes
35.
If V(x,y,z) = x^2 + y^2 + z^2, what is the magnitude of the electric field at point (1, 2, 3)? —
2 * sqrt(14)
36.
What is the relationship between electric field and equipotential surfaces? —
The electric field is perpendicular to the equipotential surface.
37.
Which of the following statements best describes electric potential? —
The work done in bringing a unit positive charge from infinity to that point against the electric field.
38.
Which statement is correct regarding equipotential surfaces? —
Work done moving charge along them is zero.
39.
If the potential energy of a charge q at a point is U, the work done by the electric field in moving the charge from that point to infinity (where potential is zero) is: —
-U
40.
The electric potential inside a charged conductor is: —
Uniform and equal to the potential at the surface
41.
The electric potential at the surface of a positively charged conducting sphere is V. What is the potential at a point inside the sphere at a distance r from the center (r < R)? —
V
42.
Which of the following is a correct formula for electric potential (V) due to a point charge (q) at a distance (r)? —
V = kq/r
43.
The electric potential at a point P due to a dipole depends on the distance r from the dipole and the angle theta between the dipole moment vector and the position vector as: —
V proportional to cos(theta)/r^2
44.
The work done to move a charge q from point A to point B is given by q(V_B - V_A). If A and B are on the same equipotential surface, then: —
V_A = V_B
45.
What is the SI unit of electric potential? —
Joule per Coulomb
46.
In an electric field, equipotential lines are closer where the electric field is: —
Stronger
47.
The electric potential at the center of a positively charged conducting sphere is: —
Equal to the potential at the surface
48.
Consider two concentric spherical shells with charges +Q and -Q. The electric potential inside the inner shell is: —
Constant
49.
Two identical positive charges are placed at a separation. The electric potential midway between them is: —
Maximum
50.
If the electric field E = 0 everywhere, then the electric potential V must be: —
Constant everywhere