# Cyient Core CS Questions with Answers

8 previously-asked core cs questions from Cyient's hiring process, each with the correct answer and a worked explanation. Written against the company's actual test pattern.

_Source: Astra (https://useastra.in). Updated 2026-09-05._

### 1. Which logic gate outputs 1 only when all of its inputs are 1?

A. AND
B. OR
C. NOT
D. NAND

**Answer:** AND

**Explanation:** An AND gate outputs 1 only when every input is 1.

### 2. What is the binary equivalent of the decimal number 10?

A. 1010
B. 1100
C. 1001
D. 1110

**Answer:** 1010

**Explanation:** 10 in binary is 1010 (8 + 2).

### 3. Which data structure is used to implement breadth first search (BFS)?

A. Stack
B. Queue
C. Tree
D. Heap

**Answer:** Queue

**Explanation:** BFS explores level by level using a queue to hold the next nodes to visit.

### 4. Which of the following cannot be instantiated directly?

A. Abstract class
B. Concrete class
C. Static class
D. Final class

**Answer:** Abstract class

**Explanation:** An abstract class may have unimplemented methods and cannot be instantiated; it must be extended.

### 5. Which SQL command is used to modify existing records in a table?

A. INSERT
B. UPDATE
C. SELECT
D. ALTER

**Answer:** UPDATE

**Explanation:** UPDATE changes values in existing rows; ALTER changes table structure.

### 6. Compared with a microprocessor, a microcontroller typically has?

A. Memory and peripherals on the same chip
B. Only an ALU and nothing else
C. No registers
D. Only external cache

**Answer:** Memory and peripherals on the same chip

**Explanation:** A microcontroller integrates CPU, memory, and peripherals on one chip, unlike a microprocessor which needs external components.

### 7. Round Robin CPU scheduling is based on which concept?

A. Priority levels
B. A fixed time quantum
C. Shortest job first
D. Deadlines

**Answer:** A fixed time quantum

**Explanation:** Round Robin gives each process a fixed time slice (quantum) in turn, providing fair sharing.

### 8. Which protocol dynamically assigns IP addresses to devices on a network?

A. DNS
B. DHCP
C. FTP
D. SMTP

**Answer:** DHCP

**Explanation:** The Dynamic Host Configuration Protocol automatically assigns IP addresses to hosts.

More Cyient preparation, including the full recruitment process: https://useastra.in/campus/cyient