Top Ericsson Interview Questions: Aptitude, Verbal, and Logical Reasoning
Ericsson Recruitment Process
Ericsson's recruitment process for fresh graduate engineers typically involves four rounds:
- Aptitude Test
- Group Discussion
- Technical Interview
- HR Interview
Academic Criteria for Ericsson
- Minimum 60% marks throughout (10th, 12th, and B.Tech/BE).
- No academic backlogs.
- Maximum one-year education gap.
First Round: Aptitude Test
The aptitude test typically includes three sections:
| Section | Number of Questions | Time (minutes) | Topics |
|---|---|---|---|
| Quantitative Aptitude | 15 | 15 | Profit and loss, HCF and LCM, ages, probability, time and work, speed and distance, etc. |
| Logical Reasoning | 15 | 15 | Series, coding-decoding, statement arguments, blood relations, seating arrangements, etc. |
| Verbal Ability | 15 | 15 | Synonyms, antonyms, reading comprehension, error correction. |
Aptitude Interview Questions
- Question 1: The average age of Mansi and her grandfather is 40. Their ages are in the ratio 1:3. What is Mansi's age?
Answer:
20
Explanation: Let Mansi's age be x. Her grandfather's age is 3x. (x + 3x) / 2 = 40. Solving for x gives x = 20.
- Question 2: 25% of 350 + 35% of 250 = x. Find x.
Answer:
175
Explanation: Calculate 25% of 350 and 35% of 250, then add the results.
- Question 3: A bag has 2 blue, 3 yellow, and 2 green balls. Two balls are drawn. What's the probability that neither is green?
Answer:
10/21
Explanation: Calculate the probability of not drawing a green ball on the first draw and then the second draw.
- Question 4: John's salary is decreased by 40% and then increased by 40%. What's the net percentage change?
Answer:
16% decrease
Explanation: Use an example salary (like 100) to demonstrate the calculation.
- Question 5: Rohan's marks were wrongly entered as 93 instead of 73, increasing the class average by 0.5. How many students are in the class?
Answer:
40
Explanation: The difference in marks (20) caused an increase of 0.5 in the average. Solve for the number of students.
- Question 6: Rohan walks at 4 km/h and covers a distance in 3 hours 45 minutes. If he runs at 12.5 km/h, how long will it take?
Answer:
72 minutes
Explanation: Calculate the distance, then use distance = speed * time.
- Question 7: A rectangular park has a length: breadth ratio of 2:1. A person runs around it at 10 km/h, completing a round in 9 minutes. What's the area?
Answer:
405,000 sq. m
Explanation: Calculate the perimeter from distance = speed * time. Then solve for length and breadth, then calculate area.
- Question 8: A takes 15 days, B takes 12 days, and A, B, and C together take 5 days to do a job. How long would C take alone?
Answer:
20 days
Explanation: Find the work rates of A and B, then subtract their combined rate from the combined rate of A, B, and C to find C's rate.
- Question 9: The ratio of Aman's and Rahul's ages is 3:4. In 6 years, Aman will be 27. What is Rahul's current age?
Answer:
28 years
Explanation: Solve for Aman's current age, then use the ratio to find Rahul's age.
Verbal English Interview Questions
Analogies
- Rain : Clouds :: X : Lacrimal Sac
Answer:
Tears
Sentence Correction
- The manor is often coming to me on Sundays.
Answer:
The manor often comes to me on Sundays.
- Sham just finished the poem later.
Answer:
Sham had just finished the poem.
Reading Comprehension Questions
(Reading comprehension questions would be placed here)
Antonyms and Synonyms
(Antonym and synonym questions would be placed here)
Logical Reasoning Questions
- What's the next number in the series: 14, 28, 20, 40, 32, 64...?
Answer:
56
- Find the odd one out: Dodge, Duck, Avoid, Flee.
Answer:
Flee
- What's the next term: 8, 6, 9, 23, 87...?
Answer:
429
- What's the next term: 3, 7, 13, 27, 53...?
Answer:
107
- Fill the blank: CMN, EOP, GQR, ____, KUV
Answer:
IST
- Decode: tamceno = sky blue; cenorax = blue cheese; aplimiti = star bright. What is "bright sky"?
Answer:
mitltam
- Hari says, "He is the son of the only daughter of my brother's father." How is Hari related?
Answer:
Maternal uncle
- (Reading comprehension question would go here)
Recursion
Recursion is a programming technique where a function calls itself. It's useful for solving problems that can be broken down into smaller, self-similar subproblems. However, careful design is needed to avoid infinite loops.
Pre-increment vs. Post-increment
Pre-increment (++x) |
Post-increment (x++) |
|---|---|
| Increments the variable *before* its value is used in the expression. | Increments the variable *after* its value is used in the expression. |
Characteristics of the C Programming Language
- Reliability
- Portability
- Efficiency
- Flexibility
- Modularity
Embedded C
Embedded C is a version of C tailored for embedded systems (microcontrollers). It often includes extensions for direct hardware manipulation.
Structured, Object-Oriented, and Non-structured Programming
| Programming Paradigm | Description | Examples |
|---|---|---|
| Structured | Code organized into functions; emphasizes control flow. | C, Pascal |
| Object-Oriented | Code organized around objects (data and methods); supports concepts like inheritance and polymorphism. | C++, Java |
| Non-Structured | Less organized; may be harder to maintain. | Early versions of BASIC, COBOL |
Modifiers in C
Modifiers (like short, long, unsigned) alter the size and range of data types.
Variable Declaration vs. Definition in C
| Declaration | Definition |
|---|---|
| Specifies the type and name of a variable; does not allocate memory. | Allocates memory and assigns a value; a variable can only be defined once. |
Virtual Functions in C++
Virtual functions support runtime polymorphism. The specific function to be called is determined at runtime, based on the object's type.
Method Overloading in OOP
Method overloading allows a class to have multiple methods with the same name but different parameter lists. The correct method is selected at compile time.
Method Overriding in OOP
Method overriding occurs when a subclass provides a new implementation for a method inherited from its superclass. This enables runtime polymorphism.
Polymorphism in OOP
Polymorphism allows objects of different classes to be treated as objects of a common type, enabling flexibility in handling diverse objects.
Data Abstraction in OOP
Data abstraction hides implementation details, exposing only essential information to the user.
Encapsulation in OOP
Encapsulation bundles data and the methods that operate on that data within a class, protecting data integrity and promoting modularity.
Inheritance in Java
Inheritance allows classes to inherit properties and methods from parent classes.
Constructors in OOP
Constructors initialize objects when they're created. They have the same name as the class and no return type.
Destructors in OOP
Destructors are used to release resources held by an object (like memory) when the object is destroyed. They are called automatically.
Linked Lists
Linked lists are dynamic data structures where elements (nodes) are linked together using pointers.
Binary Search Trees (BSTs)
Binary search trees are binary trees where the left subtree of a node contains values smaller than the node's value, and the right subtree contains values larger.
Push and Pop Methods (Stacks)
| Push | Pop |
|---|---|
| Adds an element to the top of the stack. | Removes and returns the top element from the stack. |
Stack vs. Array
| Stack | Array |
|---|---|
| LIFO (Last-In, First-Out). | Elements accessed by index. |
Doubly Linked Lists
In a doubly linked list, each node has pointers to both the next and previous nodes.
Queues
Queues are FIFO (First-In, First-Out) data structures. Elements are added to the rear and removed from the front.
Queue Applications
- Task scheduling.
- Buffering data.
Stacks
Stacks are LIFO (Last-In, First-Out) data structures. Elements are added and removed from the top.
Graphs
Graphs represent nodes and connections between them.
Priority Queues
Priority queues prioritize elements based on some criteria.
Time Complexity of Linked List Insertion
Inserting at the beginning is O(1); inserting at the end is O(n).
Coupling Mechanisms in Electrical Circuits
Coupling mechanisms describe how energy is transferred between components in an electrical circuit. Types of coupling are:
- Conductive Coupling: Direct electrical connection between components.
- Inductive Coupling: Energy transfer through magnetic fields (susceptible to electric field noise).
- Capacitive Coupling: Energy transfer through electric fields (susceptible to magnetic field noise).
ACSR Cable
ACSR (Aluminum Conductor Steel-Reinforced) cable is a type of high-capacity power transmission cable. The steel core provides strength, and the aluminum strands provide conductivity.
Control Systems
A control system manages and regulates a system's behavior to achieve a desired output. Open-loop systems don't use feedback, while closed-loop systems use feedback to adjust the output.
RLC Circuit
An RLC circuit contains a resistor (R), an inductor (L), and a capacitor (C). The current flow is governed by a second-order differential equation.
Transformers
Transformers transfer electrical energy between circuits, changing voltage levels. Applications include power transmission, impedance matching, and isolation.
Alternator vs. Generator
| Alternator | Generator |
|---|---|
| Produces AC power; usually more efficient; commonly used in vehicles. | Can produce AC or DC power; generally less efficient; used for larger-scale power generation. |
Effect of Doubling Series Current
Doubling the current in a series circuit (with constant resistance) halves the voltage across each resistor.
Types of Semiconductors
- Intrinsic (pure)
- Extrinsic (doped):
- N-type (extra electrons)
- P-type (missing electrons/holes)
Zener Diode
A Zener diode is a special diode that allows current to flow in the reverse direction when a certain voltage is exceeded. It's often used for voltage regulation.
Transistor Usage
Transistors amplify or switch electronic signals.
Series Resistors
Resistors in series divide the voltage applied across them.
NPN and PNP Transistors
NPN and PNP transistors are used in electronic circuits for amplification and switching. Their operation differs based on the type of semiconductor materials and the direction of current flow.
Laser Diodes
Laser diodes are semiconductor devices that emit coherent light. They are used in a variety of applications.
Reverse Polarity
Reverse polarity is a wiring error where hot and neutral are reversed. Check the wiring at the outlet and the receptacle to correct it.
FPGA (Field-Programmable Gate Array)
An FPGA is a programmable logic device that can be configured to implement various digital circuits. They are highly flexible and are used in many applications.
Two-Phase Motors
Two-phase motors use two AC voltages 90 degrees out of phase. They are less common now.
Rectifiers
Rectifiers convert AC to DC. Types include half-wave and full-wave rectifiers.
Analog vs. Digital Circuits
| Analog | Digital |
|---|---|
| Processes continuous signals. | Processes discrete signals (0s and 1s). |