Quantum Computing: question bank

Q1

FoundationCore practice

What is the basic unit of classical information that can be either 0 or 1?

Your answer

Q2

FoundationCore practice

In quantum computing, what is the quantum version of a classical bit called, which can exist in a superposition of states?

Your answer

Q3

FoundationCore practice

What does the term 'superposition' mean for a qubit?

A qubit can be 0 and 1 at the same timeA qubit can only be 0 or 1, never bothA qubit can be any value between 0 and 1 like a dimmer switchA qubit disappears when not observed

Q4

FoundationCore practice

What happens to a qubit's superposition when you measure it?

It stays in superposition foreverIt collapses to a definite state of either 0 or 1It becomes entangled with the measuring deviceIt switches to a random superposition

Q5

FoundationCore practice

Two qubits are described as 'entangled.' What does this mean about their measurement outcomes?

They always give the same result when measuredTheir outcomes are correlated in ways that no classical explanation can account forThey can send instant messages to each otherThey share the same physical wire

Q6

FoundationCore practice

Which quantum phenomenon allows a quantum computer to potentially solve certain problems faster than any classical computer by exploring many solutions simultaneously?

SuperpositionEntanglement aloneWave-particle dualityQuantum tunneling alone

Q7

FoundationCore practice

A single qubit is in the state |psi> = (3/5)|0> + (4/5)|1>. What is the probability of measuring this qubit in state |0>? Give your answer as a fraction.

Numerator/Denominator

Q8

FoundationCore practice

A qubit is in the state |psi> = (1/2)|0> + (sqrt(3)/2)|1>. What is the probability of measuring |1>?

Numerator/Denominator

Q9

FoundationCore practice

How many classical bits of information are needed to describe the complete state of two qubits?

Your answer

Q10

FoundationCore practice

What is the name of the quantum gate that flips a qubit state, analogous to the classical NOT gate?

Your answer

Q11

FoundationCore practice

A quantum computer has 3 qubits. How many possible basis states exist in the combined state space?

Your answer

Q12

FoundationCore practice

Which of the following is NOT a requirement for quantum computation according to DiVincenzo's criteria?

A scalable physical system with well-defined qubitsThe ability to initialize qubits to a simple fiducial stateThe ability to perform projective measurement on all qubits simultaneouslyA set of universal quantum gatesLong decoherence times relative to gate operation times

Q13

FoundationCore practice

What is the result of applying the Hadamard gate H to the state |0>?

Your answer

Q14

FoundationCore practice

In quantum computing, what does 'decoherence' refer to?

The process of entangling two qubits into a Bell stateThe loss of quantum information due to interaction with the environmentThe amplification of quantum signals to classical levelsThe speedup achieved by quantum algorithms over classical ones

Q15

FoundationCore practice

The no-cloning theorem states that it is impossible to create an identical copy of an arbitrary ________ quantum state.

Your answer

All 59 questions