Quantum Computing: Two Marks Important Questions and Answers

Applied Physics CSIE II:

UNIT IV: Quantum Computing

IMPORTANT PART A QUESTIONS AND ANSWERS

1. Define Quantum cellular Automata.

A Quantum Cellular Automata consist of an array of quantum device cells in a locally interconnected architectures.

2. Distinguish between classical bit and Quantum bit.

Classical bit

1. A bit also known as a classical bit can be in the state 0 or state 1, and measuring a bit at any time results in one of two possible outcomes.

2. A classical bit can be either 1 (or) 0

3. Classical bit concept in used in computers.

Quantum bit

1. A qubit (quantum bit) is the basic unit of information in quantum computing. A qubit uses the quantum mechanical phenomena of of super position to achieve a linear combination of two states.

2. Quantum bit (or) Qubit can be 0,1 (or) any protion of 0 and 1.

3. Quantum bit concept is used in Quantum computers.

3. What is meant by Quantum states?

The quantum state of a system is described by a complex function Ψ, which depends on the coordinate x and on time

i.e., Quantum state = Ψ(x,t)

The wave function encodes all the information about the system. We know |Ψ(x,t)|²dx is the probability of finding the position of the particles and yields a result in the interval x→x+dx.

3. What are Quantum states?

Quantum gates are operations that manipulate qubits using reversible, matrix‒based transformations and allow quantum computing to perform tasks impossible for classical computers.

4. Define Pauli gates?

Pauli gates are the three fundamental single‒qubit quantum gates: X, Y, and Z.

5. Draw the symbol and write the truth table for CNOT gate.

The Symbolic representation of CNOT gate is as shown below.

6. List out the advantages of Quantum computing over classical computing.

Advantages of Quantum computing

i. Works under the principle of Quantum Mechanics

ii. Quantum computing is done using qubits.

iii. In quantum computing 0's and 1's can be represented simultaneously.

iv. It process many possibilities simultaneously

v. In quantum computing the power increases exponentially in proportion to the numbers of qubits.

vi. Quantum computers are incredibly fast and effective.

vii. They solve complex problems.

viii. Quantum computing is used to run complex simulation.

Disadvantages of Classical computing

i. Works using Boolean logic.

ii. Classical computing is done using bits.

iii. In classical computing, we can represent either 0 (or) 1. Both cannot be represented at the same time.

iv. It process the information Sequencially.

v. In classical computing the power increases in a 1:1 relationship to the number of transistors.

vi. Classical computing is slow and ineffective.

vii. They do not solve complex problems.

viii. Classical computing shall not be used to run complex simulations.

7. Give any four applications of Quantum Computing.

Some of the applications of quantum computing is listed below. viz.

(i) Quantum computing is used in Artificial intellegence and Machine learning.

(ii) It plays a vital role in drug design & development.

(iii) They are applied in cyber security and cryptography.

(iv) Quantum Computing is used in weather forecasting.

(v) They are also used in logistics optimisation, financial modelling etc.,

(vi) In research developments, they are used in computational sciences research.

8. Prove T² = S

8. Prove S² = Z