100+ Engineer Trainee Interview Questions and Answers for Freshers

The question is about finding the total number of handshakes in a meeting of 10 people.

• Each person shakes hands with 9 others.

• Total handshakes = 10 x 9 / 2 = 45.

The minimum number of socks to be picked to obtain at least 1 rightly colored pair is 3.

• Pick 2 socks of different colors first, then the next sock picked will definitely match one of the colors already picked.

• In the worst case scenario, the first 2 socks picked will be of different colors.

• Therefore, the minimum number of socks to be picked is 3.

To merge two CSV files with 2 columns each in Python, use the pandas library.

• Import the pandas library

• Read the two CSV files into pandas DataFrames

• Merge the DataFrames using a common column as the key

• Save the merged DataFrame to a new CSV file

A technical interview for Engineer Trainee covering topics such as CMOS, latch, flip flops, MOSFET, and dynamic memory.

• CMOS stands for Complementary Metal-Oxide-Semiconductor and is a type of technology used in microprocessors and digital logic circuits.

• A latch is a type of digital circuit that can store one bit of information.

• The main difference between a latch and a flip flop is that a flip flop has a clock input and can store information for a longer period of time.

• To make...read more

A left join retrieves all records from the left table and matched records from the right table.

• Use the LEFT JOIN keyword to combine rows from two tables based on a related column.

• Syntax: SELECT columns FROM table1 LEFT JOIN table2 ON table1.column = table2.column;

• Example: SELECT a.id, a.name, b.salary FROM employees a LEFT JOIN salaries b ON a.id = b.emp_id;

• If there is no match, NULL values will be returned for columns from the right table.

Fluid is a substance that flows and takes the shape of its container. Bernoulli's Equation relates pressure, velocity, and elevation in a fluid flow.

• Fluid is a substance that deforms continuously under an applied shear stress, no matter how small.

• Bernoulli's Equation: P + 1/2ρv^2 + ρgh = constant, where P is pressure, ρ is density, v is velocity, and h is height.

• Pressure term (P): Represents the internal energy per unit volume due to molecular collisions.

• Kinetic energy term (...read more

Program to swap value of two variables without using a third variable.

• Use arithmetic operations to swap values

• Add both variables and store the sum in one variable

• Subtract the value of one variable from the sum and store it in the other variable

• Subtract the value of the other variable from the sum and store it in the first variable

Use a loop to iterate through the array and keep track of the maximum and second-maximum numbers.

• Initialize two variables to store the maximum and second-maximum numbers.

• Iterate through the array and update the variables accordingly.

• Handle edge cases like when the array has less than two elements.

Pass-by-value is a method of passing arguments to a function where the actual value of the argument is copied to a new variable.

• In pass-by-value, a copy of the actual value of the argument is passed to the function.

• Any changes made to the parameter inside the function do not affect the original value outside the function.

• Primitive data types like integers, floats, and characters are typically passed by value.

• Example: int x = 10; foo(x); // the value of x (10) is copied to a n...read more

Cloud computing is a network of remote servers hosted on the internet to store, manage, and process data, while grid computing is a distributed computing model that relies on a network of computers to work together on a task.

• Cloud computing provides on-demand access to a shared pool of configurable computing resources, while grid computing involves the coordination of disparate resources to solve a complex problem.

• In cloud computing, resources are typically virtualized and sc...read more

Hypothesis testing is a statistical method to test a hypothesis about a population parameter. P-value is the probability of observing a test statistic as extreme as the one computed from the sample data, assuming the null hypothesis is true.

• Hypothesis testing involves formulating a null hypothesis and an alternative hypothesis

• A test statistic is computed from the sample data and compared with a critical value or p-value

• If the p-value is less than the significance level, the n...read more

AC is sold in Electronics shops because it is an electrical appliance that utilizes electronic components for its operation.

• ACs use electronic components like capacitors, resistors, and microcontrollers for regulating temperature and controlling functions.

• Electronics shops specialize in selling a wide range of electronic devices, including appliances like ACs.

• ACs are considered as part of the electronics category due to their reliance on electronic technology for operation.

SQL is a language used to manage relational databases. MySQL is a popular open-source relational database management system. MongoDB is a NoSQL database.

• SQL is a language used to communicate with and manage relational databases.

• MySQL is a popular open-source relational database management system.

• MongoDB is a NoSQL database that stores data in a flexible, JSON-like format.

• SQL databases use tables to store data, while MongoDB uses collections and documents.

• SQL databases are goo...read more

Program to print prime numbers

• Start with a loop from 2 to n (number to check)

• For each number, check if it is divisible by any number from 2 to its square root

• If not divisible, it is a prime number and print it

The operating system in Apple phones is iOS.

• iOS is a mobile operating system developed by Apple Inc.

• It is the second most popular mobile operating system in the world.

• iOS is known for its user-friendly interface and security features.

• Examples of Apple phones that run on iOS are iPhone 12, iPhone 11, and iPhone SE.

To operate 4 different light bulbs under different trigger conditions, use a combination of switches, timers, sensors, and programming.

• Use individual switches to control each light bulb independently.

• Set up timers to automatically turn on/off specific light bulbs at scheduled times.

• Utilize sensors such as motion sensors or light sensors to trigger certain light bulbs based on environmental conditions.

• Program a microcontroller or smart home system to control the operation of a...read more

The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time.

• Entropy in a closed system tends to increase over time

• Heat energy naturally flows from hot to cold objects

• Efficiency of energy conversion processes is limited by the second law of thermodynamics

Machine learning is a subset of AI that involves training machines to learn from data. Deep learning is a subset of machine learning that uses neural networks to learn from large amounts of data.

• Machine learning involves training machines to learn from data and make predictions or decisions based on that data.

• Deep learning is a subset of machine learning that uses neural networks to learn from large amounts of data.

• Deep learning is particularly useful for tasks such as image ...read more

The critical temperature of steel is the temperature at which it loses its magnetic properties.

• The critical temperature of steel is around 770°C (1420°F).

• Above this temperature, steel becomes non-magnetic and undergoes a phase change.

• The critical temperature varies depending on the type of steel and its composition.

Creep is the slow, time-dependent deformation of a material under constant load, while fatigue is the weakening of a material due to repeated loading and unloading.

• Creep is a time-dependent phenomenon, while fatigue is a cyclic phenomenon.

• Creep occurs at high temperatures and constant stress, while fatigue occurs at lower temperatures and varying stress levels.

• Creep leads to permanent deformation, while fatigue can lead to crack initiation and propagation.

• Examples of creep in...read more

To make a transistor, semiconductor material can be used to create a structure with three layers: emitter, base, and collector.

• Start by doping the semiconductor material with impurities to create the different layers.

• Use lithography and etching techniques to define the structure of the transistor.

• Add metal contacts to the different layers to allow for electrical connections.

• Test the transistor to ensure proper functionality and characteristics.

• Examples: Silicon can be doped w...read more

Types of steel include carbon steel, alloy steel, stainless steel, and tool steel. They can be differentiated based on their composition, properties, and applications.

• Carbon steel contains primarily carbon and iron, with low amounts of other elements. It is commonly used in construction and manufacturing.

• Alloy steel contains additional elements such as manganese, silicon, and copper to enhance its properties. It is used in automotive and aerospace industries.

• Stainless steel c...read more

Basic electronics components include resistors, capacitors, diodes, transistors, and integrated circuits.

• Resistors: Used to control the flow of electric current.

• Capacitors: Store and release electrical energy.

• Diodes: Allow current to flow in one direction.

• Transistors: Amplify or switch electronic signals.

• Integrated Circuits: Contain multiple electronic components on a single chip.

Distribution in power transmission involves delivering electricity from substations to consumers, with transformers adjusting voltage levels.

• Distribution networks connect substations to end-users, ensuring reliable electricity supply.

• Transformers step down high transmission voltages to safer levels for residential and commercial use.

• Example: A transformer reduces 11kV from a substation to 230V for household appliances.

• Distribution systems include overhead lines, underground c...read more

A boiler is a closed vessel in which water or other fluid is heated. 2 level control of boiler involves maintaining water level. Cv is a formula for valve capacity. Different types of pressure gauges include bourdon tube, diaphragm, and digital.

• Boiler is a closed vessel used to heat water or other fluids.

• 2 level control of boiler involves maintaining water level at two different points to ensure safe operation.

• Cv is the formula for valve capacity and is calculated as the flow...read more

Interface in Java defines a set of methods that a class must implement.

• Interface in Java is a blueprint of a class. It only contains method signatures without the body.

• Classes can implement multiple interfaces but can only extend one class.

• Example: interface Animal { void eat(); } class Dog implements Animal { public void eat() { System.out.println("Dog is eating"); }}

We use sample over population to save time, money and resources.

• Sampling is less time-consuming and cost-effective than studying the entire population.

• Sampling helps to reduce errors and biases that may occur in studying the entire population.

• Sampling is useful when the population is too large to study in its entirety.

• Sampling can provide accurate results if the sample is representative of the population.