NEETPhysicsMagnetic Effects of Current
Match the current-carrying wire configurations in List-I with the magnitude of the net magnetic field at the specified reference point in List-II. In all cases, the wires carry a steady current I and R represents a characteristic distance or radius. (A) Center of a full circular loop of radius R (I) ₀ I 4 R [1 + 2 ] (B) A point at a perpendicular distance R from a long infinite straight wire (II) ₀ I 4 R (C) Center o
Options
- A(A)-(II), (B)-(III), (C)-(IV), (D)-(I)
- B(A)-(IV), (B)-(III), (C)-(I), (D)-(II)
- C(A)-(IV), (B)-(II), (C)-(III), (D)-(I)
- D(A)-(IV), (B)-(III), (C)-(II), (D)-(I)
Correct answer
D. (A)-(IV), (B)-(III), (C)-(II), (D)-(I)
Step-by-step solution
(A) The magnetic field at the center of a full circular loop of radius R is given by the standard formula B = ₀ I 2 R . This matches with (IV). (B) The magnetic field at a perpendicular distance R from a long infinite straight wire is B = ₀ I 2 R . This matches with (III). (C) For a semi-circular arc connected to radial wires, the radial segments produce zero magnetic field at the center because the current element d l is parallel or anti-parallel to the position vector r . The net field is due only to the semi-cir