Completion Oil Tools Engineer Interview Questions and Answers

Swapping two numbers without using a temp variable

• Use arithmetic operations to swap the values

• Add the two numbers and store the result in the first variable

• Subtract the second variable from the result and store it in the second variable

• Subtract the second variable from the first variable to get the original value of the second variable

• Example: a=5, b=7; a=a+b=12, b=a-b=5, a=a-b=7

The current in a transformer is made by inducing voltage across the primary coil.

• The primary coil of a transformer is connected to an alternating current (AC) source.

• The alternating current in the primary coil creates a changing magnetic field.

• This changing magnetic field induces a voltage across the secondary coil.

• The induced voltage in the secondary coil causes a current to flow through it.

• The current in the secondar...read more

DC shunt motors are a type of direct current motor that have a parallel field winding and a series armature winding.

• DC shunt motors have a parallel field winding and a series armature winding.

• They are commonly used in applications that require constant speed and moderate starting torque.

• The speed of a DC shunt motor can be controlled by varying the field current or the armature voltage.

• DC shunt motors are widely used i...read more

A DC shunt motor is a type of direct current motor that has a shunt field winding connected in parallel with the armature winding.

• The field winding and armature winding are connected in parallel

• The shunt motor has a relatively constant speed-torque characteristic

• The speed of the motor can be controlled by varying the field current

• The motor provides good starting torque

• The shunt motor is commonly used in applications wh...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.