Lokesh Machines Mechanical Engineer Interview Questions and Answers

Name mangling is a technique used by compilers to give unique names to functions and variables to avoid naming conflicts.

• Name mangling is used in C++ to support function overloading.

• It is also used in Python to avoid naming conflicts in modules.

• Name mangling can make it difficult to access variables and functions from outside the class in which they are defined.

• In C++, name mangling can be seen by using the 'nm' comman

A diesel generator works by converting diesel fuel into mechanical energy which is then converted into electrical energy.

• Diesel fuel is injected into the combustion chamber where it ignites and creates high pressure gases that push the piston down, creating mechanical energy.

• The mechanical energy is then converted into electrical energy through the use of an alternator.

• The alternator uses a magnetic field and a conduct...read more

A diesel engine works by compressing air in the cylinder, which heats up and ignites the fuel injected into the cylinder.

• Air is drawn into the cylinder and compressed by the piston

• The compressed air heats up and ignites the fuel injected into the cylinder

• The explosion pushes the piston down, which turns the crankshaft and powers the engine

• Diesel engines are more efficient than gasoline engines because they compress the...read more

A train doesn't need a differential because its wheels are fixed to the same axle and rotate at the same speed.

• Train wheels are fixed to the same axle

• Wheels rotate at the same speed

• Differential is used in vehicles with wheels that rotate at different speeds

• Differential allows for smooth turning

Petrol engines have lower compression ratios compared to diesel engines.

• Petrol engines have lower compression ratios to prevent knocking or detonation.

• Diesel engines have higher compression ratios to ignite the fuel without spark plugs.

• Higher compression ratios in diesel engines result in better fuel efficiency and torque.

• Petrol engines require lower compression ratios to accommodate the lower octane rating of petrol f...read more

Abstract Factory is a creational design pattern that provides an interface for creating families of related objects.

• Abstract Factory is used when we need to create families of related objects without specifying their concrete classes.

• It provides an interface for creating objects of related classes without specifying their concrete classes.

• It encapsulates a group of factories that have a common theme.

• It promotes loose c...read more

Range based map iteration can be done using a for-each loop or iterators.

• Use a for-each loop to iterate over the map elements.

• Alternatively, use iterators to traverse the map.

• The range-based for loop is preferred for its simplicity and readability.

• Example: for(auto const& [key, value] : myMap) { //do something with key and value }

Detached threads are independent threads that run separately from the main thread. Joined threads are threads that wait for the main thread to finish.

• Detached threads are created using pthread_detach() function

• Joined threads are created using pthread_join() function

• Detached threads do not need to be explicitly terminated

• Joined threads must be explicitly terminated using pthread_exit() or return statement

• Detached thread...read more

Static code analysis tools are software programs that analyze source code to find potential issues and improve code quality.

• Static code analysis tools scan code without executing it

• They can detect issues such as security vulnerabilities, coding errors, and performance problems

• Examples of static code analysis tools include SonarQube, ESLint, and Checkstyle

Command to list currently running threads in linux

• Use the 'ps' command with the 'H' option to display threads in a hierarchy

• Use the 'top' command to display threads in real-time

• Use the 'htop' command for an interactive display of threads

No, arithmetic operations cannot be performed on unique pointers.

• Unique pointers are used to manage the lifetime of dynamically allocated objects.

• They cannot be copied or assigned, only moved.

• Arithmetic operations are not defined for pointers, including unique pointers.