Match List-I (scientist) with List-II (work or idea linked with the name).
| List-I | List-II |
|---|---|
| (A) Meissner | (I) Quantum theory of superconductivity, proposed in 1957 |
| (B) Bardeen, Cooper and Schrieffer | (II) First electric telegraph, built in 1833 |
| (C) Ampere | (III) Perfect diamagnetism in superconductors |
| (D) Gauss | (IV) Hypothesis that all magnetic phenomena come from circulating currents |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(III), (B)-(I), (C)-(IV), (D)-(II)
(A) Meissner — This matches (III) perfect diamagnetism in superconductors. A superconductor pushes the magnetic field out of itself completely, with \( \chi=-1 \). This is called the Meissner effect.
(B) Bardeen, Cooper and Schrieffer — This matches (I). Their quantum theory (BCS theory) explains both perfect conductivity and perfect diamagnetism of a superconductor. It was proposed in 1957.
(C) Ampere — This matches (IV). By Ampere’s hypothesis, all magnetic effects can be explained by circulating currents. A current loop acts as a magnetic dipole.
(D) Gauss — This matches (II). Besides his work in mathematics and physics, Gauss helped to build the first electric telegraph in 1833.
NCERT (2026-27):
Diamagnetism – “… The phenomenon of perfect diamagnetism in superconductors is called the Meissner effect, after the name of its discoverer. …”
Points to Ponder – “… A quantum-mechanical theory by Bardeen, Cooper, and Schrieffer (BCS theory) explains these effects. The BCS theory was proposed in 1957 …”
Bar magnet as an equivalent solenoid – “… We mentioned Ampere’s hypothesis that all magnetic phenomena can be explained in terms of circulating currents.”
Karl Friedrich Gauss (1777 – 1855) – “… Along with Wilhelm Welser, he built the first electric telegraph in 1833. …”