🧷 Authentic Classroom Explanation by IAS Monk

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📌 The Question

Which one of the following is the context in which the term “qubit” is mentioned?

(a) Cloud Services
(b) Quantum Computing
(c) Visible Light Communication Technologies
(d) Wireless Communication Technologies

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✅ Answer

(b)

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🧑‍🏫 Classroom Explanation

A qubit (quantum bit) is the fundamental unit of information in quantum computing, analogous to the classical bit in conventional computing.

• A classical bit can exist only in one of two states: 0 or 1.
• A qubit, however, can exist in a superposition of states 0 and 1 simultaneously.
• Qubits can also exhibit quantum entanglement, enabling correlations that classical systems cannot replicate.

These properties allow quantum computers to process certain classes of problems far more efficiently than classical computers, especially in areas like cryptography, materials science, optimisation, and drug discovery.

Hence, the term “qubit” is specifically associated with Quantum Computing, making option (b) correct.

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🔍 Curiosity Raiser

If a qubit can be both 0 and 1 at the same time, how does a quantum computer ever give a definite answer?

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📚 Enrichment Notes

• Physical realisations of qubits:
  • Superconducting circuits
  • Trapped ions
  • Photons
  • Spin states of electrons
• Key quantum properties:
  • Superposition
  • Entanglement
  • Quantum interference
• Why qubits matter:
  • Enable exponential state space growth
  • Foundation of quantum supremacy claims
• UPSC linkage:
  • National Quantum Mission
  • Post-quantum cryptography
  • Strategic technologies

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🪔 IAS Monk Whisper

“A classical bit chooses. A qubit contemplates all possibilities—until reality asks a question.”