40+ Marrow Interview Questions and Answers

To check continuity of a wire inside a wall, use a multimeter and connect it to the starting and end points of the wire.

• Turn off power to the circuit before testing

• Set the multimeter to continuity mode

• Connect one probe to the starting point and the other to the end point

• If the multimeter beeps or shows a reading, the wire has continuity

• If there is no continuity, the wire may be broken or disconnected

Object-oriented programming is a programming paradigm that uses objects to represent and manipulate data. Procedural programming is a programming paradigm that uses procedures or functions to structure the program.

• Object-oriented programming focuses on objects and their interactions.

• Procedural programming focuses on procedures or functions.

• In object-oriented programming, data and behavior are encapsulated within objects.

• In procedural programming, data and behavior are separat...read more

Universal Gates are gates that can be used to implement any logic function. OR gate can be drawn from a Universal Gate.

• Universal Gates include NAND and NOR gates

• NAND and NOR gates can be used to implement any logic function

• OR gate can be drawn from a NAND gate by connecting both inputs together

• OR gate can be drawn from a NOR gate by connecting both inputs together and inverting the output

Counters are used to count the number of clock pulses and generate output signals. Shift registers are used to store and shift data.

• Counters are sequential circuits that count the number of clock pulses and generate output signals.

• They can be used in applications such as frequency dividers, event counters, and timers.

• Shift registers are used to store and shift data in a serial manner.

• They can be used in applications such as data storage, data transfer, and parallel-to-serial ...read more

RDBMS is a type of DBMS that stores data in a structured manner using tables and enforces relationships between them.

• DBMS is a software system that manages databases, while RDBMS is a specific type of DBMS.

• RDBMS uses a tabular structure to store data, with each table consisting of rows and columns.

• RDBMS enforces the ACID properties (Atomicity, Consistency, Isolation, Durability) to ensure data integrity.

• RDBMS supports SQL (Structured Query Language) for managing and manipulat...read more

Servomotor and stepper motor are both used for precise control of motion, but differ in their operation and applications.

• Servomotors use feedback control to maintain a specific position or speed, while stepper motors move in discrete steps.

• Servomotors are typically used in applications requiring high precision and accuracy, such as robotics and CNC machines.

• Stepper motors are commonly used in applications requiring precise positioning, such as 3D printers and linear actuators...read more

Early binding and late binding are two different approaches to linking functions or methods to their respective code.

• Early binding is done at compile-time, where the function call is resolved before the program is executed.

• Late binding is done at runtime, where the function call is resolved during the program's execution.

• Early binding provides better performance as the function call is already resolved.

• Late binding allows for more flexibility as the function call can be deter...read more

Primary key is a unique identifier for a record in a database table. Candidate key is a potential primary key. Composite key is a combination of two or more columns to uniquely identify a record.

• Primary key uniquely identifies a record in a table

• Candidate key is a potential primary key that can be chosen as the primary key

• Composite key is a combination of two or more columns to uniquely identify a record

• Example: In a table of students, the student ID can be the primary key, w...read more

There are no classes in C as it is a procedural programming language.

• C is a procedural programming language, not an object-oriented one.

• It does not have the concept of classes or objects.

• Instead, it uses functions and structures to organize code.

• Structures can be used to create user-defined data types.

• For example, a structure can be defined to represent a person with attributes like name, age, and address.

Big Data refers to large and complex datasets that cannot be easily managed or processed using traditional data processing techniques.

• Big Data is characterized by the 3Vs: Volume, Velocity, and Variety.

• Volume refers to the vast amount of data generated and collected from various sources.

• Velocity refers to the speed at which data is generated and needs to be processed in real-time.

• Variety refers to the different types and formats of data, including structured, unstructured, an...read more

Johnson Counter is a digital circuit that counts in a cyclic pattern.

• It is a type of shift register with feedback

• It has a sequence of n bits that cycle through 2^n-1 states

• It is used in digital clocks, frequency dividers, and memory address decoding

• Example: 4-bit Johnson counter has a sequence of 0001, 0010, 0100, 1000, 0001, ...

• It can be implemented using D flip-flops or JK flip-flops

Abstract methods are methods without implementation. They are used to enforce implementation by subclasses.

• Abstract methods are declared with the 'abstract' keyword and end with a semicolon instead of a method body.

• They are used in abstract classes to enforce implementation by subclasses.

• Subclasses must provide an implementation for all abstract methods or be declared as abstract themselves.

• Abstract methods are useful for creating a common interface for a group of related cla...read more

Data can be analyzed by using various techniques such as data mining, machine learning, and statistical analysis.

• Use data mining techniques to discover patterns and relationships in the data

• Apply machine learning algorithms to make predictions and classifications

• Utilize statistical analysis to identify trends and draw conclusions

• Use visualization tools to present the data in a meaningful way

• Employ parallel processing and distributed computing to handle the large volume of dat...read more

C is a procedural programming language while C++ is an extension of C with added features of object-oriented programming.

• C is a procedural language, while C++ supports both procedural and object-oriented programming.

• C++ has additional features like classes, objects, inheritance, and polymorphism.

• C++ supports exception handling and templates, which are not available in C.

• C++ allows function overloading and operator overloading, which are not supported in C.

• C++ has a standard t...read more

Modulation is the process of varying a carrier signal's properties to transmit information efficiently.

• Modulation is used to transmit information over long distances.

• It allows multiple signals to be transmitted simultaneously without interference.

• Modulation helps in improving the signal quality and reducing noise.

• Different modulation techniques include amplitude modulation (AM), frequency modulation (FM), and phase modulation (PM).

• For example, FM modulation is used in radio b...read more

Latches and flip flops are sequential logic circuits used to store data. Flip flops are edge-triggered while latches are level-triggered.

• Latches are level-triggered and can be transparent or opaque

• Flip flops are edge-triggered and can be positive or negative edge-triggered

• Latches are simpler and faster than flip flops

• Flip flops are more reliable and less prone to glitches than latches

• Examples of latches include SR latch, D latch, and JK latch

• Examples of flip flops include SR ...read more

Analog to digital conversion techniques include pulse code modulation, delta modulation, and sigma-delta modulation.

• Pulse code modulation (PCM) samples the analog signal at regular intervals and quantizes each sample into a binary code.

• Delta modulation (DM) approximates the slope of the analog signal and encodes the difference between the approximated value and the actual value.

• Sigma-delta modulation (SDM) oversamples the analog signal and uses a feedback loop to reduce quant...read more

8085 is called 8 bit processor because it can process 8 bits of data at a time.

• 8085 has an 8-bit data bus and can process 8 bits of data at a time

• It has an 8-bit accumulator and can perform arithmetic and logical operations on 8-bit data

• It has 16-bit address bus which can address up to 64 KB of memory

• Examples of 8-bit processors include Intel 8080, Zilog Z80, and MOS Technology 6502

Functions are used in a program to modularize code, improve code reusability, enhance readability, and simplify debugging.

• Functions help break down complex tasks into smaller, manageable parts.

• They promote code reusability by allowing the same code to be used multiple times.

• Functions enhance code readability by organizing code into logical blocks.

• They simplify debugging as errors can be isolated and fixed within a specific function.

• Functions enable collaboration by allowing d...read more

An abstract class in Java is a class that cannot be instantiated and is used as a blueprint for other classes.

• An abstract class can have both abstract and non-abstract methods.

• It can have abstract methods without any implementation.

• It can also have non-abstract methods with implementation.

• Abstract classes are meant to be extended by other classes.

• To use an abstract class, it must be extended and its abstract methods must be implemented.

Flags in 8086 and their high and low conditions

• 8086 has 9 flags: Carry, Parity, Auxiliary Carry, Zero, Sign, Trap, Interrupt, Direction, Overflow

• Flags can be set or reset based on the result of arithmetic and logical operations

• High condition means the flag is set, while low condition means the flag is reset

A PID controller is a feedback control loop that calculates an error value as the difference between a desired setpoint and a measured process variable.

• The block diagram of a PID controller consists of three main components: the proportional, integral, and derivative terms.

• The proportional term produces an output that is proportional to the error signal.

• The integral term produces an output that is proportional to the integral of the error signal over time.

• The derivative term ...read more

Find equivalent resistance of the given circuit

• Identify series and parallel connections

• Use Ohm's law to calculate individual resistances

• Combine resistances using series and parallel rules

• Final answer should be in Ohms

Microprocessor is a single chip CPU while microcontroller is a complete computer on a chip.

• Microprocessor is used in general purpose computing while microcontroller is used in embedded systems.

• Microprocessor has limited on-chip peripherals while microcontroller has on-chip peripherals like timers, ADC, etc.

• Microprocessor requires external memory and peripherals while microcontroller has them on-chip.

• Examples of microprocessors are Intel Pentium, AMD Ryzen while examples of mi...read more

Explanation of different terminals of BJT

• BJT has three terminals: emitter, base, and collector

• Emitter is heavily doped and has the highest concentration of charge carriers

• Base is lightly doped and controls the flow of charge carriers from emitter to collector

• Collector is moderately doped and collects the charge carriers from the base

• The direction of current flow is from emitter to collector

The program counter is a register that keeps track of the next instruction to be executed in a computer program.

• The program counter is a special register in a computer's central processing unit (CPU).

• It holds the memory address of the next instruction to be executed.

• After each instruction is executed, the program counter is incremented to point to the next instruction.

• In case of conditional or unconditional jumps, the program counter is updated to the new memory address.

• The p...read more

A multivibrator is an electronic circuit that generates a continuous output waveform of a specified shape and frequency.

• Multivibrators are used in various applications such as timing circuits, frequency dividers, and waveform generators.

• There are three types of multivibrators: astable, monostable, and bistable.

• Astable multivibrators produce a continuous square wave output with no stable state.

• Monostable multivibrators generate a single output pulse of a specific duration when...read more

A latch is level-sensitive and stores data as long as the enable signal is active, while a flip flop is edge-triggered and stores data only on the rising or falling edge of the clock signal.

• Latches are level-sensitive, while flip flops are edge-triggered.

• Latches store data as long as the enable signal is active, while flip flops store data only on the rising or falling edge of the clock signal.

• Latches are simpler and have lower power consumption compared to flip flops.

• Flip fl...read more

Transducers are devices that convert one form of energy into another. They are used in various fields including engineering and medicine.

• Electrical transducers convert electrical signals into physical quantities and vice versa. Example: thermocouples.

• Mechanical transducers convert mechanical energy into electrical signals and vice versa. Example: strain gauges.

• Optical transducers convert light energy into electrical signals and vice versa. Example: photodiodes.

• Chemical transd...read more

Draw XOR gate truth table

• XOR gate has two inputs and one output

• Output is 1 only if inputs are different

• Truth table: 0 XOR 0 = 0, 0 XOR 1 = 1, 1 XOR 0 = 1, 1 XOR 1 = 0

Transistor is a semiconductor device used for amplification and switching of electronic signals.

• Transistor is made up of three layers of semiconductor material - P-type, N-type, and P-type.

• It has three terminals - emitter, base, and collector.

• Transistor can be used as an amplifier to increase the strength of a weak signal.

• It can also be used as a switch to turn a circuit on or off.

• Transistors are used in various electronic devices such as radios, televisions, computers, and m...read more

8085 has 5 interrupts. TRAP, RST 7.5, RST 6.5, RST 5.5, INTR

• 8085 has 5 interrupts: TRAP, RST 7.5, RST 6.5, RST 5.5, INTR

• TRAP is a non-maskable interrupt

• RST 7.5, RST 6.5, and RST 5.5 are maskable interrupts

• INTR is a maskable interrupt and can be enabled or disabled by setting the interrupt enable flip-flop

• Interrupts are used to handle external events and improve the efficiency of the system

A D-flip flop can be used to create a counter by connecting the output of one flip flop to the input of the next.

• Connect the output of one D-flip flop to the input of the next

• Use the clock signal to trigger the flip flops

• Set the initial value of the counter

• Use additional logic gates if necessary to control the counter behavior

Functions are blocks of code that perform a specific task and can be reused throughout a program.

• Functions are used to break down a program into smaller, manageable parts.

• They improve code reusability and modularity.

• Functions can take input parameters and return output values.

• Examples of functions include calculating the square root of a number or sorting an array.

VFD stands for Variable Frequency Drive which is used to control the speed of an induction motor.

• VFD is an electronic device that controls the frequency and voltage supplied to an induction motor.

• It can be used to vary the speed of the motor as per the requirement.

• VFDs are commonly used in industries to save energy and improve efficiency.

• They can also be used to reduce mechanical stress on the motor and increase its lifespan.

• Example: A VFD can be used to control the speed of ...read more

A foreign key is a column or a set of columns in a database table that refers to the primary key of another table.

• Foreign keys establish relationships between tables in a relational database.

• They ensure referential integrity and maintain data consistency.

• Foreign keys can be used to enforce constraints and enable cascading updates or deletes.

• They allow data from multiple tables to be linked together based on common values.

• Foreign keys are typically used in database normalizati...read more

BJT has three operating regions: active, saturation, and cutoff.

• Active region: both junctions are forward-biased.

• Saturation region: both junctions are reverse-biased.

• Cutoff region: base-emitter junction is reverse-biased and base-collector junction is forward-biased.

• BJT operates as an amplifier in the active region.

• BJT operates as a switch in the saturation and cutoff regions.

Op-amp is an electronic device that amplifies the difference between two input voltages.

• Op-amp stands for operational amplifier.

• It has a high gain and can amplify signals.

• It has two input terminals, one inverting and one non-inverting.

• The output voltage is the amplification of the voltage difference between the input terminals.

• Op-amps are widely used in various applications such as amplifiers, filters, oscillators, and comparators.

BJT is a current-controlled device while FET is a voltage-controlled device.

• BJT stands for Bipolar Junction Transistor while FET stands for Field Effect Transistor.

• BJT has a higher gain and faster switching speed than FET.

• FET has a higher input impedance and lower noise than BJT.

• BJT is commonly used in low-power applications while FET is commonly used in high-power applications.

• Examples of BJT include NPN and PNP transistors while examples of FET include JFET and MOSFET.

I look for quality, durability, and precision in moulds.

• Quality of the material used in the mould

• Durability of the mould to withstand repeated use

• Precision in the mould's design and manufacturing process

• Ability to produce consistent and accurate parts

• Ease of maintenance and repair

• Compatibility with the intended manufacturing process

NPN and PNP transistors are drawn using three layers of semiconductor material.

• Draw two vertical lines representing the two outer layers of the transistor.

• Draw a diagonal line connecting the top of the left line to the bottom of the right line for NPN transistor.

• Draw a diagonal line connecting the top of the right line to the bottom of the left line for PNP transistor.

• Add arrows to indicate the direction of current flow.

• Label the emitter, base, and collector for each transist...read more

Capacitors are electronic components that store energy in an electric field. There are different types of capacitors based on their dielectric material.

• Types of capacitors include ceramic, electrolytic, tantalum, film, and paper capacitors.

• Dielectric materials used in capacitors include ceramic, aluminum oxide, tantalum pentoxide, polyester, and polypropylene.

• Ceramic capacitors are commonly used in high-frequency circuits, while electrolytic capacitors are used in power suppl...read more

PID controller is a feedback control mechanism used in engineering to regulate a system's output.

• PID stands for Proportional-Integral-Derivative

• It continuously calculates an error value as the difference between a desired setpoint and a measured process variable

• The controller then adjusts the output to minimize the error

• Proportional control responds to the current error, integral control responds to the error over time, and derivative control responds to the rate at which the...read more

A Silicon Controlled Rectifier (SCR) is a type of semiconductor device used for controlling electric power.

• SCR is a three-terminal device that acts as a switch, conducting current only when a specific gate signal is applied.

• It is commonly used in power control applications such as motor speed control, lighting control, and power supply regulation.

• SCRs are known for their high reliability, long lifespan, and ability to handle high current and voltage levels.

• Once triggered, an ...read more

OOP is a programming paradigm that uses objects to represent and manipulate data and behavior.

• Encapsulation: bundling data and methods together in a class

• Inheritance: creating new classes from existing ones

• Polymorphism: using a single interface to represent different types

• Abstraction: simplifying complex systems by breaking them into smaller, manageable parts