Quantum Computing Solved MCQs

 

Introduction to Quantum Computing

1. What is Quantum Computing?
A) A type of computing that uses quantum mechanics principles ✅
B) A superfast classical computer
C) A type of artificial intelligence
D) A blockchain-based technology

2. Which fundamental principle does Quantum Computing rely on?
A) Newtonian mechanics
B) Classical physics
C) Quantum mechanics ✅
D) Relativity theory

3. What is the basic unit of quantum information?
A) Byte
B) Bit
C) Qubit ✅
D) Pixel

4. Which property allows qubits to exist in multiple states simultaneously?
A) Superposition ✅
B) Entanglement
C) Classical coherence
D) Parallelism

5. What is the key advantage of Quantum Computing over Classical Computing?
A) It consumes more energy
B) It is slower but more accurate
C) It can solve complex problems exponentially faster ✅
D) It uses traditional bits

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Qubits and Quantum States

6. What is a qubit?
A) A binary unit like a classical bit
B) A quantum unit that can exist in multiple states at once ✅
C) A data storage unit
D) A microprocessor component

7. Which phenomenon allows two qubits to be interconnected regardless of distance?
A) Superposition
B) Entanglement ✅
C) Quantum tunneling
D) Qubit decoherence

8. How does superposition work?
A) A qubit can be 0, 1, or both at the same time ✅
B) A qubit can only be 0 or 1
C) A qubit remains in a fixed state
D) A qubit disappears after measurement

9. What happens when a qubit is measured?
A) It collapses into one of its possible states ✅
B) It remains in superposition
C) It entangles with another qubit
D) It loses its quantum properties permanently

10. What does quantum entanglement mean?
A) When two qubits interact and share information instantaneously ✅
B) When a qubit collapses after measurement
C) When a qubit exists in multiple states
D) When a qubit disappears

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Quantum Gates and Circuits

11. What is a quantum gate?
A) A logic gate for classical computers
B) A mathematical function
C) A basic operation that manipulates qubits ✅
D) A physical door in a quantum processor

12. What is the quantum equivalent of a classical NOT gate?
A) Hadamard gate
B) X-gate ✅
C) CNOT gate
D) SWAP gate

13. Which gate creates superposition in a quantum circuit?
A) Hadamard gate ✅
B) X-gate
C) CNOT gate
D) T-gate

14. What is the purpose of a CNOT gate?
A) It flips the target qubit if the control qubit is 1 ✅
B) It creates superposition
C) It measures a qubit
D) It collapses quantum states

15. Quantum gates operate on which mathematical structure?
A) Matrices ✅
B) Vectors
C) Scalars
D) Polynomials

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Quantum Algorithms

16. Which quantum algorithm is used for factorizing large numbers?
A) Grover’s Algorithm
B) Shor’s Algorithm ✅
C) Deutsch-Jozsa Algorithm
D) Q-learning Algorithm

17. Which quantum algorithm provides a quadratic speedup for search problems?
A) Shor’s Algorithm
B) Grover’s Algorithm ✅
C) Bellman’s Algorithm
D) Dijkstra’s Algorithm

18. What is the advantage of quantum algorithms over classical ones?
A) They always provide exact solutions
B) They are probabilistic and can solve problems exponentially faster ✅
C) They work only on small datasets
D) They eliminate all computational errors

19. What does quantum speedup refer to?
A) The ability of quantum computers to solve problems much faster than classical ones ✅
B) The overclocking of quantum processors
C) The ability of qubits to be cooled down
D) The faster execution of classical algorithms

20. Which type of problems can quantum computers solve more efficiently than classical computers?
A) Simple arithmetic
B) Cryptographic and optimization problems ✅
C) Word processing
D) Image compression

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Quantum Hardware and Challenges

21. What material is commonly used to build qubits?
A) Silicon
B) Superconducting materials ✅
C) Copper
D) Plastic

22. What is quantum decoherence?
A) The loss of quantum state due to environmental interaction ✅
B) The doubling of quantum states
C) The increase in processing speed
D) The expansion of a quantum processor

23. What is the biggest challenge in building a large-scale quantum computer?
A) Power consumption
B) Qubit stability and error correction ✅
C) Lack of software
D) Limited storage capacity

24. Which company developed the first commercial quantum computer?
A) IBM
B) Google
C) D-Wave ✅
D) Microsoft

25. What temperature is required for superconducting quantum computers to operate?
A) Room temperature
B) Near absolute zero ✅
C) 100°C
D) -50°C