Ampere’s law and applications to wires and solenoids - One Line Questions

1. Ampere's law relates the magnetic field around a closed loop to the electric current passing through the loop. Mathematically, it is stated as: — ∮ B ⋅ dl = μ₀I_enc
2. To apply Ampere's law to a solenoid, we choose an Amperian loop that is: — A rectangle with one side inside and one side outside the solenoid, parallel to the axis
3. Ampere's law is most useful for calculating the magnetic field when the symmetry of the problem allows for: — An Amperian loop where the magnetic field is constant in magnitude and parallel to the loop
4. Ampere's law is valid for: — Any shape of Amperian loop
5. In a solenoid, the magnetic field lines are most densely packed: — Throughout the interior
6. Consider a circular loop of radius R carrying current I. The magnetic field at the center of the loop is: — B = (μ₀I) / (2R)
7. What is the magnetic field at the center of a circular loop of radius R carrying current I, if the loop is made of wire with cross-sectional area A? — The cross-sectional area does not affect the field at the center
8. Consider a long straight wire carrying a current I. What is the magnitude of the magnetic field at a perpendicular distance r from the wire? — B = (μ₀I) / (2πr)
9. Consider a long straight wire carrying current I. The magnetic field at a distance r is B. If the wire is hollow with inner radius r₁ and outer radius r₂, and the current flows uniformly through the cross-section, what is the field at r < r₁? — 0
10. For a hollow cylindrical conductor of inner radius r₁ and outer radius r₂ carrying a uniform current I, what is the magnetic field at a distance r such that r₁ < r < r₂? — B = (μ₀I (r² - r₁²)) / (2πr(r₂² - r₁²))
11. A toroid is a solenoid bent into a circular shape. For a toroid with N turns and carrying current I, the magnetic field inside the toroid at a radius r is: — B = (μ₀NI) / (2πr)
12. What is the magnitude of the magnetic field inside a long solenoid carrying current I, with n turns per unit length? — B = μ₀nI
13. If the permeability of the medium inside a solenoid is μ instead of μ₀, the magnetic field inside becomes: — B = μnI
14. A thin wire carries a current I. If the wire is bent into a circular loop of radius R, the magnetic field at the center is B_center. If it is bent into a square loop of side length L, the magnetic field at the center is B_square. Which statement is true? — B_center < B_square
15. The magnetic field lines inside a solenoid are: — Straight lines parallel to the axis
16. To determine the direction of the magnetic field around a straight current-carrying wire, one can use: — The Right-Hand Grip Rule
17. Ampere's law is a consequence of: — Biot-Savart law
18. Ampere's law is a macroscopic law, while Biot-Savart law is a microscopic law. Ampere's law can be derived from Biot-Savart law under conditions of: — High symmetry
19. If a solenoid is not long and ideal, the magnetic field: — Is weaker near the ends than in the middle
20. Which of the following statements about Ampere's law is FALSE? — It is derived from Gauss's law for magnetism.
21. What happens to the magnetic field inside a solenoid if the number of turns per unit length (n) is increased, while keeping the current (I) constant? — It increases
22. What happens to the magnetic field inside a solenoid if the current (I) is increased, while keeping the number of turns per unit length (n) constant? — It increases
23. If we consider an Amperian loop that encloses no net current, then the line integral of B around that loop is: — Zero
24. What is the magnetic flux through the surface enclosed by an Amperian loop if no net current passes through the loop? — Zero
25. Ampere's law is applicable to which type of currents? — Only steady currents
26. The magnetic field of a long straight wire is proportional to: — 1/r
27. The magnetic field lines around a long straight current-carrying wire are: — Concentric circles centered on the wire
28. Ampere's law is particularly useful when dealing with conductors carrying current that exhibit: — High degree of symmetry
29. If the current in a long straight wire is doubled, the magnetic field at a given distance from the wire will: — Be doubled
30. If the distance from a long straight wire carrying current I is doubled, the magnetic field at that point will: — Be halved
31. A current loop creates a magnetic field. If the current is doubled, the magnetic field at any point will: — Be doubled
32. If the current in a solenoid is reversed, the direction of the magnetic field inside the solenoid: — Reverses
33. Ampere's law is particularly useful for calculating magnetic fields in situations with: — All of the above
34. The magnetic field outside an ideal toroid is: — Zero
35. The magnetic field strength inside a solenoid is directly proportional to: — The current
36. The magnetic field at a point inside a long solenoid depends on: — The current and the number of turns per unit length
37. In Ampere's law, ∮ B ⋅ dl = μ₀I_enc, what does 'μ₀' represent? — The permeability of free space
38. For a current distribution with cylindrical symmetry, the magnetic field depends on: — The radial distance only
39. In Ampere's law, ∮ B ⋅ dl = μ₀I_enc, what does 'I_enc' represent? — The total current enclosed by the loop
40. The magnetic field inside a toroid is: — Circular, centered on the toroid axis
41. A solenoid is a coil of wire wound into a tightly packed helix. For an ideal, long solenoid, the magnetic field inside is approximately: —
42. The unit of magnetic field (B) is Tesla (T). Which of the following is equivalent to Tesla? — Weber/meter²
43. The magnetic field inside a toroid is strongest where the windings are: — Tightly packed
44. Consider two long straight wires placed parallel to each other, separated by a distance d, and carrying currents I₁ and I₂ in the same direction. The magnetic field at a point exactly midway between them is: — Dependent on the permeability of the medium
45. If two long straight wires carry currents in opposite directions, the magnetic field at a point midway between them is: — Non-zero and directed perpendicular to the plane containing the wires
46. A long straight wire carries a current I. If a cylindrical surface of radius r is chosen as the Amperian loop, coaxial with the wire, the integral ∮ B ⋅ dl is: — 2πr B
47. The magnetic field outside an ideal, long solenoid is approximately: — Zero
48. What is the magnetic field at a point inside a long solenoid far from the ends, if the solenoid is carrying a current I and has n turns per unit length? — μ₀nI
49. What is the magnetic field at a distance r from the axis of a long solenoid, outside the solenoid? — 0
All One Line Questions
E-Book Ampere’s law and applications to wires and solenoids Online Test Ampere’s law and applications to wires and solenoids Question Bank Ampere’s law and applications to wires and solenoids