IBM A1000-112: Assessment: Fundamentals of Quantum Computation Using Qiskit v0.2x Developer Practice Exam 2025: Latest Questions

What is the primary difference between a classical bit and a quantum bit (qubit)?

In Qiskit, which method is used to add a Hadamard gate to a quantum circuit?

A developer needs to create an entangled Bell state |Φ+⟩ = (|00⟩ + |11⟩)/√2 using Qiskit. What is the correct sequence of gates to apply?

What does the Bloch sphere represent in quantum computing?

Which quantum algorithm provides a quadratic speedup for searching an unsorted database compared to classical algorithms?

A quantum developer is experiencing errors when running a circuit on real quantum hardware but not on simulators. The circuit has long sequences of two-qubit gates. What is the most likely cause?

In Qiskit, what is the purpose of the transpile() function?

What is quantum entanglement and why is it important for quantum computing?

A researcher is implementing the Quantum Approximate Optimization Algorithm (QAOA) for a combinatorial optimization problem. Which statement best describes the role of the classical optimizer in this algorithm?

When simulating a quantum circuit with noise models in Qiskit, a developer observes that certain qubits consistently produce higher error rates. What characteristic of real quantum hardware is the noise model most likely representing?

A quantum developer needs to measure only the first and third qubits of a 5-qubit quantum circuit in Qiskit v0.2x. Which approach correctly implements this selective measurement?

What is the primary advantage of using the Aer simulator's 'statevector_simulator' backend compared to the 'qasm_simulator' backend?

A developer implements a quantum circuit that should create the state |ψ⟩ = (|00⟩ + |11⟩)/√2. However, measurements show equal probabilities for all four basis states. What is the most likely error in the circuit implementation?

In quantum computing, what does the term 'quantum volume' primarily measure?

When implementing the Quantum Fourier Transform (QFT) in Qiskit, which gate sequence is NOT part of the standard QFT implementation?

A quantum circuit is transpiled for execution on IBM quantum hardware. Which statement about the transpilation process is most accurate?

What is the computational complexity advantage of Grover's algorithm for unstructured search compared to classical algorithms?

A developer needs to implement a custom quantum gate that performs a rotation around an arbitrary axis on the Bloch sphere. Which Qiskit approach provides the most flexibility for this requirement?

In the context of variational quantum algorithms like VQE (Variational Quantum Eigensolver), what is the role of the classical optimizer?

A quantum circuit executes successfully on a simulator but fails with an error on real IBM Quantum hardware stating 'qubit connectivity constraint violated.' What is the most likely cause and solution?

A quantum developer is implementing a quantum phase estimation algorithm and needs to apply controlled versions of a unitary operator U raised to different powers. Which Qiskit method is most appropriate for creating U^(2^k) efficiently?

When running a quantum circuit on IBM Quantum hardware, a developer notices that two-qubit gate errors are significantly impacting results. Which strategy would BEST minimize the impact of gate errors?

What is the primary advantage of using the Statevector simulator compared to the Qasm simulator in Qiskit?

A developer needs to implement a quantum circuit that prepares the state |ψ⟩ = (|00⟩ + |11⟩)/√2 and then applies a phase of π to the |11⟩ component only. What is the most efficient sequence of gates in Qiskit?

In the context of quantum error mitigation, what does the Zero-Noise Extrapolation (ZNE) technique accomplish?