Quantum Computing Basics- 2026 Student Revision Notes

Fundamental Concepts & Industry Standards (100 Questions) 1. What is the basic unit of information in a quantum computer? A) Bit B) Byte C) Qubit (Quantum Bit) D) Q-node Correct Answer: C) Qubit (Quantum Bit) 2. "Superposition" refers to the ability of a qubit to: A) Be in a state of 0 only B) Be in a state of 1 only C) Be in a state of 0, 1, or both simultaneously until measured D) Move faster than the speed of light Correct Answer: C) Be in a state of 0, 1, or both simultaneously until measured 3. Which phenomenon describes qubits becoming linked so that the state of one instantly influences the state of another, regardless of distance? A) Quantum Interference B) Quantum Entanglement C) Quantum Decoherence D) Quantum Annealing Correct Answer: B) Quantum Entanglement 4. "Quantum Supremacy" (or Quantum Advantage) means: A) Quantum computers have replaced all desktop PCs B) A quantum computer can perform a calculation that is practically impossible for a classical supercomputer C) Quantum computers are now sent into space D) A computer that can think like a human Correct Answer: B) A quantum computer can perform a calculation that is practically impossible for a classical supercomputer 5. What is the main cause of errors in quantum calculations? A) Slow internet connection B) Decoherence (interaction with the environment) C) Not enough RAM D) Overheating of the monitor Correct Answer: B) Decoherence (interaction with the environment) 6. In 2026, most quantum computers require temperatures near "Absolute Zero" because: A) To save on electricity bills B) To minimize thermal noise and maintain qubit stability C) To keep the room comfortable for scientists D) To make the metal parts stronger Correct Answer: B) To minimize thermal noise and maintain qubit stability 7. "Quantum Gates" are used to: A) Keep unauthorized people out of the lab B) Manipulate the state of qubits to perform logic operations C) Protect the computer from viruses D) Connect the quantum computer to the cloud Correct Answer: B) Manipulate the state of qubits to perform logic operations 8. Which of these is a famous quantum algorithm for factoring large numbers? A) Grover's Algorithm B) Shor's Algorithm C) Dijkstra's Algorithm D) PageRank Correct Answer: B) Shor's Algorithm 9. "Grover's Algorithm" is primarily used for: A) Factoring integers B) Searching an unsorted database faster than classical algorithms C) Sending emails D) Creating 3D graphics Correct Answer: B) Searching an unsorted database faster than classical algorithms 10. What is "NISQ" era in quantum computing? A) New Intelligent Super Quality B) Noisy Intermediate-Scale Quantum C) Next Integrated System Quantum D) Non-Interference Small Qubits Correct Answer: B) Noisy Intermediate-Scale Quantum 11. "Quantum Annealing" is a specific type of quantum computing used for: A) General purpose programming B) Optimization problems (e.g., D-Wave systems) C) Watching 4K videos D) Storing backup data Correct Answer: B) Optimization problems (e.g., D-Wave systems) 12. "Post-Quantum Cryptography" (PQC) aims to: A) Make computers faster B) Develop encryption methods that are secure against attacks by quantum computers C) Delete all old passwords D) Use qubits to send secret messages Correct Answer: B) Develop encryption methods that are secure against attacks by quantum computers