Torque on a dipole in a uniform electric field, electric flux, Gauss law and applications - One Line Questions
1.
For a dipole placed in a uniform electric field, the torque is maximum when the angle between the dipole moment and the electric field is: —
90 degrees
2.
The stable equilibrium position of an electric dipole in a uniform electric field is when the angle between the dipole moment and the electric field is: —
0 degrees
3.
Gauss's Law can be used to find the electric field due to a point charge q at a distance r by choosing a Gaussian surface as: —
A sphere centered on the charge
4.
Gauss's Law is not generally useful for calculating the electric field of: —
An arbitrarily shaped charged object
5.
The orientation of a dipole with minimum potential energy in a uniform electric field is when the dipole moment is: —
Parallel to the electric field
6.
The dipole moment vector points from the negative charge towards the positive charge. In a uniform electric field, the dipole tends to align itself: —
Parallel to the field
7.
Gauss's Law is a direct consequence of: —
Coulomb's Law
8.
What is the electric flux through a closed surface if it contains an electric dipole? —
Zero
9.
What is the electric flux through a closed surface that encloses no net charge? —
Zero
10.
What is the condition for minimum torque on a dipole in a uniform electric field? —
Dipole moment is parallel to the electric field
11.
Electric flux is defined as the integral of the electric field over a surface: Φ = ∫ E ⋅ dA. If the electric field is uniform and perpendicular to a flat surface of area A, the flux is: —
EA
12.
Which quantity is conserved in any process involving electric charges, according to Gauss's Law? —
Net charge enclosed
13.
Which of the following statements is INCORRECT regarding electric flux? —
Electric flux depends on the exact shape of the Gaussian surface, not just the enclosed charge.
14.
Electric flux is proportional to the number of electric field lines passing through a surface. If the surface area is doubled while keeping the field constant and perpendicular, the flux: —
Doubles
15.
Consider a Gaussian surface enclosing a net charge Q. If another charge q is brought near the surface but outside it, the net flux through the surface: —
Remains unchanged
16.
Gauss's Law is particularly useful for calculating the electric field of charge distributions with: —
High symmetry
17.
Consider a point charge q enclosed within a sphere. If the radius of the sphere is doubled, how does the electric flux through the sphere change? —
It remains the same
18.
What is the net torque on an electric dipole in a uniform electric field when it is in stable equilibrium? —
Minimum (zero)
19.
If a dipole is in equilibrium in a uniform electric field, the net torque on it is: —
Zero
20.
For a dipole aligned anti-parallel to a uniform electric field, the torque is: —
Zero
21.
A dipole is in unstable equilibrium if its potential energy is: —
Maximum
22.
The unit of electric flux, Vm, is equivalent to: —
N m²/C
23.
The net electric flux through a closed surface is given by Gauss's Law: Φ = Q_enclosed / ε₀. If the enclosed charge is positive, the flux is: —
Positive
24.
The direction of the dipole moment is from the negative charge to the: —
Positive charge
25.
What is the SI unit of electric flux? —
Volt meter (Vm)
26.
If an electric field is uniform, the net flux through any closed surface entirely within that field, enclosing no charge, is: —
Zero
27.
A dipole is in unstable equilibrium in a uniform electric field when its dipole moment is: —
Anti-parallel to the electric field
28.
The torque on a dipole in a uniform electric field is zero when the dipole moment is: —
Either parallel or anti-parallel to the electric field
29.
A dipole of dipole moment p is placed in a uniform electric field E. What is the torque experienced by the dipole? —
p x E
30.
The potential energy of an electric dipole of dipole moment p in a uniform electric field E is given by: —
-p.E
31.
The work done in rotating a dipole from an angle θ₁ to θ₂ in a uniform electric field E is given by: —
pE(cosθ₂ - cosθ₁)
32.
If an electric field line enters a closed surface, it contributes: —
Negative flux
33.
An electric dipole consists of two equal and opposite charges, +q and -q, separated by a distance 2a. If the dipole moment is p, what is its magnitude? —
2aq
34.
The net flux through a closed surface is zero. This implies that: —
There is no charge enclosed by the surface.
35.
If a closed surface is placed in a non-uniform electric field, the net electric flux through the surface is zero if: —
The net charge enclosed is zero.
36.
Electric flux is a measure of: —
The number of electric field lines passing through a surface
37.
Gauss's Law relates the electric flux through a closed surface to: —
The total charge enclosed by the surface
38.
When is the potential energy of a dipole in a uniform electric field equal to zero? —
When the dipole moment is perpendicular to the field
39.
If the net charge enclosed by a Gaussian surface is zero, then the electric flux through the surface is: —
Zero
40.
If a dipole is placed in a non-uniform electric field, the net force on the dipole is generally: —
Non-zero
41.
If the electric field is parallel to the area vector of a surface, the electric flux is: —
Maximum
42.
For a dipole aligned perpendicular to a uniform electric field, the torque is: —
Maximum
43.
If the electric field lines are diverging from a closed surface, the net flux is: —
Positive
44.
What is the magnitude of the electric field inside a uniformly charged solid conducting sphere? —
Zero
45.
If a dipole moment p is rotated by 180 degrees in a uniform electric field E, the change in potential energy is: —
2pE
46.
What is the magnitude of the electric field at a distance r from an infinitely long charged wire with linear charge density λ, according to Gauss's Law? —
λ / (2πε₀r)
47.
Application of Gauss's Law: The electric field outside an infinitely long charged cylinder with radius R and linear charge density λ at a distance r > R is: —
λ / (2πε₀r)
48.
Application of Gauss's Law: The electric field inside a uniformly charged spherical shell of radius R is: —
Zero
49.
What is the magnitude of the electric field at a distance r from an infinite plane sheet of charge with uniform surface charge density σ, according to Gauss's Law? —
σ / (2ε₀)
50.
The magnitude of the electric field at the surface of a conductor carrying a surface charge density σ is: —
σ / ε₀