IBM A1000-136 Practice Exam 2025: Latest Questions

A developer is new to quantum computing and wants to explain what measurement does in a quantum circuit. Which statement best describes measurement?

A team is writing Qiskit code and needs to compute expectation values of observables for a circuit, not just raw bitstrings. Which Qiskit capability is most appropriate?

In a quantum circuit, which gate creates an equal superposition of |0⟩ and |1⟩ when applied to a qubit initialized in |0⟩?

A user runs a circuit and gets a counts dictionary like {'00': 520, '11': 504} out of 1024 shots. What is the most appropriate interpretation of these results?

A researcher expects two qubits to be entangled (e.g., a Bell state), but the measurement results show all four bitstrings ('00','01','10','11') occurring about equally often. Which is the MOST likely cause?

A developer wants to run the same parameterized circuit many times with different parameter values and minimize overhead. What is a recommended approach on the IBM Quantum platform?

A team wants to estimate the ground-state energy of a small molecule using a variational approach on near-term hardware. Which algorithm best fits this goal?

A circuit is correct in simulation but performs poorly on hardware. The transpilation report shows many inserted SWAP operations. What is the most likely reason?

A user runs a Bernstein-Vazirani circuit to learn a hidden bitstring s. The circuit output is inconsistent across runs even in an ideal (noise-free) simulator. Which issue is the MOST plausible?

A developer needs to choose between two hardware backends for a circuit dominated by two-qubit gates. Backend A has slightly more qubits but significantly worse two-qubit error rates than Backend B. Which choice is typically best for higher fidelity results, assuming both support the required qubit count?

A new team member is confused about why measuring a qubit often changes what you can know about its state afterward. Which statement best explains measurement in quantum computing?

You are asked to run a quantum circuit on IBM hardware but want to validate logic first without queue time. Which is the most appropriate approach?

A student claims that because qubits can be in superposition, you can copy an arbitrary qubit to multiple qubits for backup. Which principle contradicts this claim?

A team is using Qiskit Runtime and wants to minimize network overhead when iterating the same circuit many times with different parameter values (e.g., variational algorithms). What is the recommended pattern?

A circuit executed on real hardware produces results that differ from the simulator. The simulator used an ideal (noise-free) model. What is the most likely reason for the mismatch?

You need to create an entangled Bell state between two qubits starting from |00>. Which gate sequence accomplishes this?

A developer receives an error indicating a circuit cannot be executed on a selected backend due to unsupported gates. What is the best next step?

A data scientist wants to use a variational algorithm (e.g., for optimization) and asks why the circuit must be run many times. What is the primary reason variational algorithms require repeated circuit executions?

A user builds a circuit intended to show quantum interference: two Hadamard gates in sequence on the same qubit, then measurement. In an ideal system, what outcome distribution should they expect and why?

You run a Grover-style search demonstration but observe a much lower-than-expected success probability on hardware compared to an ideal simulator. You suspect the circuit depth is too high. Which adjustment is most directly aligned with improving success probability on near-term devices?

A learner notices that measuring a 1-qubit circuit sometimes returns 0 and sometimes returns 1, even though the circuit looks the same each time. Which explanation best describes why this happens on a real quantum system?

A team is building a quantum experiment pipeline in Python and wants to run the same parameterized circuit at multiple parameter values without reconstructing the full circuit each time. What is the recommended approach in Qiskit?

A developer runs a circuit on a hardware backend and receives unexpectedly poor results compared to a simulator. They suspect noise is dominating. Which next step is most appropriate to diagnose and reduce the impact of readout (measurement) errors in results?

A user submits a job to an IBM Quantum backend but it remains queued for a long time. They need faster turnaround for iterative development while keeping results representative of hardware constraints. What is the best practice?

A team wants to use Grover's algorithm to search an unstructured database of size N for a single marked item. They ask what improvement Grover provides over classical search in terms of query complexity. Which statement is correct?