IBM A1000-099: Assessment: Foundations of Quantum Computing Intermediate Practice Exam: Medium Difficulty 2025

A quantum algorithm requires preparing a state where three qubits are in superposition with equal probability amplitudes for all basis states. After applying Hadamard gates to all three qubits initially in |0⟩, what is the probability of measuring the state |101⟩?

A developer is implementing a quantum circuit that needs to flip the phase of only the |11⟩ state in a two-qubit system while leaving all other computational basis states unchanged. Which gate combination achieves this controlled phase flip most efficiently?

During the execution of Grover's search algorithm on a database of 16 items, approximately how many iterations of the Grover operator should be applied to maximize the probability of finding the marked item?

A research team observes that their quantum circuit results show significant deviation from expected values when run on real IBM quantum hardware compared to simulator results. The circuit has a depth of 150 gates across 5 qubits. What is the most likely primary cause of this discrepancy?

In implementing a quantum teleportation protocol, after Alice performs a Bell measurement on her entangled qubit and the qubit to be teleported, what operations must Bob apply to his entangled qubit based on Alice's measurement outcomes to recover the original state?

A quantum developer needs to implement Shor's algorithm for factoring a 15-bit number. Considering the resource requirements, what is a key challenge they will face when attempting to run this on current IBM Quantum systems?

When using Qiskit to run a quantum circuit on IBM Quantum hardware, a developer notices their job remains queued for an extended period. They want to optimize their workflow. Which approach would be most effective for reducing overall job completion time?

A quantum circuit implements the Quantum Fourier Transform (QFT) on 4 qubits. What is the primary computational advantage of QFT compared to the classical Fast Fourier Transform (FFT) in terms of complexity?

A developer is constructing a parameterized quantum circuit in Qiskit for use in a variational quantum algorithm. They need to create a circuit where rotation angles can be updated between iterations. Which Qiskit feature should they use to efficiently implement this?

In a quantum circuit, a developer applies a Hadamard gate to the first qubit, then a CNOT gate with the first qubit as control and the second as target (both qubits start in |0⟩). What is the resulting two-qubit state and what property does it demonstrate?