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Right option is (a) Yes

Explanation: The minimum number of times an entry-controlled LOOP will run if the condition FAILS at FIRST ATTEMPT is 0. However, the minimum number of times an exit-controlled loop will run if the condition fails at first attempt is 1. Here the difference is that in an entry-controlled loop, the condition is checked before entry into the loop structure, while in an exit-controlled loop, the condition is checked after the completion of the loop structure.

Correct ANSWER is (b) Bitwise OR

The explanation: The ‘|’ operator is used to perform a bitwise OR OPERATION on any two numbers which SERVE as the operands. It performs an OR operation on each bit starting from the most significant bit to the least significant bit.

Correct option is (a) To communicate with the SD CARD Module

To elaborate: The SD.h Library in ARDUINO allows for communications between the Arduino Board and an SD Card Module for STORAGE and RETRIEVAL of data. It is dependent on the sdfatlib library which works on FAT16 and FAT32 filesystems.

Correct ANSWER is (a) Decides which type of transition to trigger on

Best explanation: There are different types of transition, RISING, FALLING, and CHANGE.

RISING – Triggers interrupt when PIN transitions from LOW to HIGH.

FALLING – Triggers interrupt when pin transitions from HIGH to LOW.

CHANGE – Triggers interrupt when pin transitions from LOW to HIGH or HIGH to LOW.

Correct answer is (b) To use more pins for interrupts

For explanation: Pin change Interrupts can be used to enable the ARDUINO to use more than one pin during the interrupt service ROUTINE. In ATMega 168 or 328 based Arduino boards, upto 20 pins can be DEDICATED to interrupts.

Correct option is (a) I2C Bus

Easy explanation: The Wire Library is used to COMMUNICATE data with the I2C (Inter IC) or TWI (Two Wire Interface) Bus which are almost IDENTICAL to each other and are used for COMMUNICATING data to different microcontrollers.

Correct OPTION is (a) UNSIGNED Int

The best explanation: The delayMicroseconds() function delays or pauses program execution for a certain AMOUNT of time. The return TYPE here is unsigned int, which means basically a number of the int DATATYPE without any plus or minus signs. This number here is denoted by microseconds.

The correct option is (d) 4

The best explanation: The ARDUINO Mega has 3 RX-TX pairs; 0&1, 19&18, 17&16 and 15&14. The Serial pins are USED for establishing and maintaining communications between the computer and the Arduino. However, once any of these RX-TX pairs are setup for serial communications, during the COURSE of the program they cannot be used for GPIO.

The correct ANSWER is (d) The Firmata Library can only be used on an ARDUINO Uno

To elaborate: The Firmata Library is used for communicating data to and from the computer. This is REQUIRED when the Arduino is required to store certain data on the computer which would be otherwise too large for the Arduino to store in its internal memory. Other uses of this library are in the field of IOT.

Right option is (a) Break up a SAMPLED signal to a finite dataset

The explanation: The ADC (Analog to Digital Convertor) CIRCUIT converts the pure analog signal to a digitized signal with discrete VOLTAGE points. However, in order to be able to perform further complicated computations on the data, we need to convert the discrete signal into a set of finite data points. This is done by mapping the values to a set of POSITIVE real INTEGERS.

Right answer is (d) No, it is not a replacement

Easiest explanation: The Arduino programming language is a subset of the C++ programming language, so the main function is also present here. However during the active development of any PROJECT using the Arduino Environment we do not encounter the main function()’s USE since it is prebuilt for that purpose to make the development simple, so that instead of worrying about LINKING the correct system functions to the main function during the development cycle of the project, the programmer only needs to worry about the ACTUAL working of his/her project.

The correct choice is (a) YES, external C/C++ libraries can be used with the Arduino code

The EXPLANATION is: Since the Arduino Language is a subset of the C++ programming language, any existing C/C++ library can be used for IMPORTING into an Arduino code. There is no RESTRICTION on the USE of external libraries since most of the Arduino ecosystem is Open-Source.

Correct answer is (d) PULSE Width Modulated Signal

The best I can EXPLAIN: The analogWrite() method in Arduino is used to generate a Pulse Width Modulated Signal since the digital circuitry in the Arduino does not allow for generation of true continuous analog WAVES. So THEREFORE, the PWM Signal is used.

Correct choice is (c) INDEPENDENT SLAVE Configuration

To EXPLAIN I would say: The Independent Slave Configuration is a type of SPI configuration where each slave is a separate chip and the master DEVICE talks to one chip at a time.

The setup is given below…

Right ANSWER is (a) Only STATIC Functions

To explain: The static keyword makes the VARIABLE only visible to one function. The DATA HELD by static variables is not erased when the function call is over. This is what differentiates any static variable with a non-static variable.

Right ANSWER is (a) To compare TWO strings

For explanation I WOULD say: The strcmp() FUNCTION takes in two arguments to work and it’s JOB is to compare two strings. it returns 0 if the first and second strings are the same, returns a number greater than 0 if the first string is greater than the second one and vice versa.

Right option is (b) null

The BEST I can explain: The shiftOut() FUNCTION takes a byte of data as input and shifts the data bit by bit out to an output pin by either moving from left to right or vice VERSA. So, it does provide us an output, HOWEVER that output is directly UPDATED to the pin, and not sent back as a return value.

Correct ANSWER is (a) initialization, conditional, increment/decrement

For explanation I WOULD say: The for-loop structure is an entry controlled looping structure. It is GENERALLY used when there is a clear starting point and ENDING point to the loop. Unlike the while loop in which the ending point may or may not be INCLUDED in the loop structure.

Right ANSWER is (a) 0

Best explanation: The flush() function is a member of the stream CLASS. The function exists to clear every character that is stored in the buffer. It accepts no ARGUMENTS since it clears the entire buffer unconditionally on being INVOKED, so no parameters are required to carry out this operation.

Right choice is (B) 2

The explanation: All binary numbers have a base of 2. This means that this NUMBER SYSTEM has only 2 digits which are 0 and 1. The base of a number system is the number of unique characters or digits that are used for representing numbers.0

The correct CHOICE is (c) Call the setup() function from the loop() function

For explanation: The setup() function is designed to RUN only at the startup of the Arduino code, in order to INITIALIZE and configure the setup before RUNNING the actual code. However it is theoretically possible to run the setup() function infinitely by calling it from the loop() function as illustrated below…

Correct answer is (b) 2

To explain: A MACRO is a constant VARIABLE that gets initialized in a PROGRAM here with the help of a preprocessor. There are two types of macros, namely object type macros and function type macros. An object type macro is one which is simply a variable NAME with a VALUE attached to it while a function type macro is one which is of the form of expression.

Correct answer is (a) The ARDUINO Code FOLLOWS the Object-Oriented ideology

The explanation is: SINCE the Arduino Programming Language is a SUBSET of the C++ Programming Language, it supports the Object-Oriented Programming approach much like C++.

Right option is (a) Yes, you can write

The explanation: The Arduino compiler actually translates or in more technical terms ‘compiles’ the code into assembly language which uses the Arduino’s instruction SET. Thus, any other language which has a compiler capable of translating or COMPILING that code into the Arduino’s instruction set in assembly can ESSENTIALLY be used for writing Arduino code.

Correct OPTION is (b) All pins except pin 2 and 3

The explanation is: ISR allows to initiate an interrupt ROUTINE in any Arduino BOARD. The interrupt service routine can be used to automate a number of functions in an Arduino. Usually a number of pins are assigned for any Board. The Arduino Uno has ISR functionality ENABLED for only pins 2 and 3.

Correct answer is (a) To automate FUNCTIONS

To explain I would say: The interrupt service routine can be used to automate a number of functions in an arduino. In a SITUATION where the entire focus of the code is bound to one function, the ISR can act as a pause for the arduino to stop the CURRENT function temporarily and divert MEMORY to ANOTHER function. That way, the entire memory of the arduino is used up in one function.

Right choice is (a) RAM

The best EXPLANATION: ‘volatile’ is a DIRECTIVE to the compiler. It makes the compiler load the variable from the Random-Access Memory instead of the STORAGE register. It is also called a variable qualifier. It can be USED if exactly precise values are to be stored.

Right choice is (a) To find x^y

To explain: The pow() function is used to find the value of a number RAISED to another number. It takes two arguments; the BASE, and the EXPONENT. The input datatypes are of the FLOAT datatype and the output is of the double datatype.

Correct choice is (b) Create a nested infinite loop within the loop() function

To explain I WOULD say: Yes, it is POSSIBLE to make the loop() function EXECUTE only once while running the code infinitely. This can be done by using an infinite loop within the loop() function so that the code never goes out of the loop and THUS never allowing the loop() function to iterate.

The correct OPTION is (a) #error

Explanation: As explained in the question, the job of the #WARNING preprocessor directive is to throw a MESSAGE to the Arduino IDE as a warning to notify the user or the programmer of something. However, it does not hinder in the COMPILATION PROCESS.

The correct option is (c) 3

The EXPLANATION: There are 3 configuration files which allow a person to tweak the CONFIGURATIONS. These include the following files; platform.txt, boards.txt, and programmers.txt. These files are all really IMPORTANT in defining the architecture for DIFFERENT processors.

Right answer is (a) Var = B101

Explanation: The concept used above is a binary formatter. If this letter is associated with the number during INITIALIZATION of the variable, the number is converted from that base to the base 10 which is the DECIMAL base. This binary formatter only works for NUMBERS which have a LENGTH of 8 bits.

The correct option is (a) C/C++

To elaborate: The Arduino CODE is basically a LIGHTLY modified version of the C++ programming language. It includes certain functions or MODULES that are SPECIFIC to the development of the Arduino platform and was preinstalled in the language by the developers.

Correct choice is (a) Length

The BEST explanation: When the SIZEOF() FUNCTION is used, it returns a number which corresponds to the length of the structure in question. It’s used by programmers for finding the, say number of elements in an array, or the number of characters in a STRING, etc…

Correct answer is (a) Unary

Best explanation: The cast OPERATOR is a unary operator which is used to convert one data TYPE into ANOTHER FORCEFULLY. One example is:

Right choice is (C) ‘\N’

To explain: The newline character is used for SHIFTING the CURSOR to the next line for any output to the MONITOR. It is mostly used for formatting output. During execution this escape sequence is converted to the OS Specific newline representation.

Right answer is (b) To find the SQUARE root of a number

The best explanation: The sqrt() function is used to find the square root of a number. It takes ONE argument; the number whose square root is to be FOUND out. This function can accept any number-based datatypes and GIVES the output in the double datatype.

Correct option is (d) 8 MICROSECONDS

Easiest explanation: The micros() function gives the up-time of the Arduino program in microseconds. This function has a RESOLUTION, i.e. the intervals in which it gives an OUTPUT. This resolution depends on the Frequency of the specific Arduino Board that its running on. On the Arduino LILYPAD it’s resolution is 8 Microseconds.

Correct OPTION is (d) 8

To explain: The bool datatype can only take 2 values; TRUE or FALSE. This takes a space of 8 bits or 1 BYTE. It’s mostly used in digital read or write operations to denote a 0V or 5V signal output or input. It can also be used for DECISION making.

Right choice is (c) UNSIGNED Long

Explanation: The micros() function gives the up-time or the time since the Arduino STARTED to run the program. The RETURN TYPE here is unsigned long, which means basically a number of the long datatype WITHOUT any plus or minus signs. This number denotes the up-time in microseconds.

Right option is (c) Yes, they can be used for all digital pins and ARDUINO Boards

Easy explanation: The tone() function generates a square wave at a constant 50% duty cycle and a specified FREQUENCY. So, if a COMMUNICATION is to be established between two devices on this basis, the receiver only has to record the different frequencies of the square WAVES and map them to a certain set of finite predefined integers in order to obtain some meaningful data from the TRANSMISSION.

Correct answer is (d) Frequency Modulation

Explanation: Any Modulation TECHNIQUE that converts an analog signal to a digital signal is of immense importance in pure digital circuits like the Arduino. These help the Arduino’s circuit to RECEIVE raw unmodulated signals from the outside and process them in a digital environment. Here frequency modulation is the only modulation technique that only WORKS with analog-to-analog signal modulation.

Correct option is (a) YES, it can call

The explanation is: In C/C++ Programming, a FUNCTION can call any other function WHETHER it be the MAIN function or any other custom defined function. In the case of the Arduino, the setup() and the loop() functions are custom predefined functions that are a part of the Arduino programming language subsystem.

Correct CHOICE is (a) 1

Easy explanation: The digitalRead() function is used to take digital signal inputs to the ARDUINO. It requires 1 argument; the pin number which would indicate which pin is to be used for that PARTICULAR operation. This will make the Arduino to START reading voltage fluctuations of the order of 0V and 5V.

The correct answer is (a) 1

For explanation I would say: The setup() function is used predominantly to configure the pins, variables, SERIAL DATA, etc. and is executed only once THROUGHOUT the entire cycle of the program. However other than the above-mentioned uses, it can also be used to EXECUTE technically all aspects of an Arduino program, but since it only RUNS one time, it’s not very useful for anything other than configuring.

The correct choice is (c) Flash

The explanation is: When the PROGMEM Utility is invoked, data being saved is diverted to the flash memory INSTEAD of the SRAM. This utility is a VARIABLE MODIFIER, which means it can change the variable policy whenever invoked.