Match List-I with List-II.
| List-I | List-II |
|---|---|
| (A) The value of 1 T expressed in gauss | (I) 0 |
| (B) The value of \(\mu_0/4\pi\) expressed in T m A-1 | (II) \(10^{4}\) |
| (C) Magnetic susceptibility \(\chi\) of a superconductor | (III) \(-1\) |
| (D) Relative magnetic permeability \(\mu_r\) of a superconductor | (IV) \(10^{-7}\) |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(II), (B)-(IV), (C)-(III), (D)-(I)
(A) The value of 1 T expressed in gauss — This matches (II) \( 10^{4} \). One gauss is \( 10^{-4} \) tesla, so one tesla is \( 10^{4} \) gauss.
(B) The value of \( \mu_0/4\pi \) expressed in T m A-1 — This matches (IV) \( 10^{-7} \). In SI units \( \mu_0 \) is fixed at \( 4\pi\times10^{-7}\ \mathrm{T\,m\,A^{-1}} \), and dividing by \( 4\pi \) leaves \( 10^{-7} \).
(C) Magnetic susceptibility \( \chi \) of a superconductor — This matches (III) \( -1 \). A superconductor expels the field lines completely. It is a perfect diamagnet.
(D) Relative magnetic permeability \( \mu_r \) of a superconductor — This matches (I) 0. With \( \mu_r=1+\chi \) and \( \chi=-1 \), the relative permeability is zero.
NCERT (2026-27):
Magnetic Field, Lorentz Force – “… Tesla is a rather large unit. A smaller unit (non-SI) called gauss (=10–4 tesla) is also often used. …”
Magnetic Field Due to a Current Element, Biot-Savart Law – “… In SI units, μ0 is fixed to be equal to 4π × 10–7 in magnitude.”
Diamagnetism – “… Here the field lines are completely expelled! χ= –1 and μr = 0. …”