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The correct OPTION is (a) Number of ELEMENTS in the array

To elaborate: The primary use of the sizeof() function is to return the length or size of an ELEMENT that is given to it. So, if this element is an array which is a collection of elements, it will give the number of elements PRESENT inside the array.

Right option is (a) The avr/pgmspace.h header FILE

The explanation: The PROGMEM Utility is contained WITHIN the avr/pgmspace.h header file and this file is to be INVOKED WHENEVER a programmer needs to use the PROGMEM Utility for his or her program. However, while using the data stored in the FLASH memory one also needs to use certain functions defined within the header file to retrieve the data.

Right option is (c) To find the tan of a NUMBER

Best explanation: The tan() function is used to find the tangent of an ANGLE. It takes one argument; the angle whose tangent is to be found out. This number is to be entered in the radian format and not the degree format. This function can accept the float datatype and gives the OUTPUT in the DOUBLE datatype.

Right answer is (d) string

Easy explanation: The substr() FUNCTION is USED to return a PORTION of a given string. It accepts 2 inputs as arguments; the lower and UPPER INDEXES. It can be used as “str.substr(a,b);” where a is the lower index and b is the upper index.

Right choice is (C) Stream.readString()

The explanation is: The Stream.readString() is a FUNCTION that belongs to the Stream CLASS. It’s capable of reading any String from a stream and then store the output into a String. This function can also be called from the Wire class. There is a TIMEOUT for this reading which is defined by the setTimeout() function.

Right answer is (a) RTC LIBRARY

For explanation: This library WORKS on Arduino Boards that have the SAMD Architecture, including the Arduino Zero, MKRZero, etc. It allows for manipulating the Internal Real Time Clock of the Arduino. The Real Time Clock MAINTAINS the current time related information and can also be used for scheduling programs.

Correct option is (c) Only one

For explanation I WOULD say: The tone() function uses the Arduino’s built in timer to generate the square wave of the necessary FREQUENCY. So the number of tone() INVOKES a board can handle depends UPON the number of timers present on that board.

Right CHOICE is (B) The compiler executes the code while the IDE gives a graphical environment for writing the code

To explain: According to the primary definitions of a compiler and an IDE, the job of DEBUGGING and EXECUTING a piece of code falls on the compiler, while the job of the IDE is to provide an easy to USE environment for writing the code in the first place.

Right choice is (a) Yes

Explanation: 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 so it can be used on any kind of data STRUCTURES allowed by the language.

Correct choice is (b) No

For EXPLANATION: The delay function will not work inside any Interrupt and it will not be ABLE to function properly in any way. So, no programmer should use it inside the code DEDICATED for running as INTERRUPTS. However delayMicroseconds() will work as it normally would.

Right answer is (a) Switch-case

For explanation: The switch case is ANOTHER TYPE of decision-making control structure which can be used as a total REPLACEMENT for the if-else structure. However, since it’s a more RIGID structure, it’s mostly used for menu driven programs.

Correct answer is (a) The programmer

The best explanation: Explicit type casting is the process wherein the programmer specifies in the code the SOURCE and destination data type of any variable WHOSE type needs to be CONVERTED. Unlike IMPLICIT type casting, here the compiler doesn’t initiate the CONVERSION until the programmer says so.

The CORRECT choice is (d) Do-While loop

To explain: An entry-controlled loop is a looping structure that performs the INITIALIZATION, condition-checking, and increment/decrement operation at the beginning of the loop. So THEREFORE, before a loop even starts to execute, a CHECK is made if the condition is satisfied or not. In an exit controlled only the condition checking is DONE after the execution.

Correct ANSWER is (a) char

Explanation: The front() function RETURNS a character from the string GIVEN as input. It takes in no arguments. It returns the first character that is present in the string. It can be used as “cout<

Correct choice is (d) 4

For explanation I would say: The data PACKET is divided into 4 sections. The FIRST section being the start bit which is usually 1. After that COMES the data frame which holds the data which can range from being 5-BITS to 9-bits. The section after the data section comes the parity section which denotes whether the number of bits in the data packet is odd or even. The final section is the stop-bit. This section can hold upto 2 bits and is used to indicate the end of the data packet.

Right OPTION is (a) Connecting the Linux processor and the MICROCONTROLLER onboard the Yun

Easiest explanation: The Arduino Yun has two processors onboard; the Atheros 9331 which is a processor that runs Linux and the Atmega32U4 which is a microcontroller. The JOB of the Bridge LIBRARY’s job is to connect these two devices and enable communication between them.

The correct CHOICE is (B) SoftwareSerial Library

Easiest explanation: The UART (Universal Asynchronous Receiver Transmitter) is a piece of hardware that allows digital communications between 2 IC’s. The pins on the ARDUINO that support this are 0 and 1. This functionality is parallel in nature, i.e. the Atmega chip on the Arduino can receive UART data and continue to work on whatever it was working on, at the same time.

The correct option is (a) Hitachi HD44780

The BEST explanation: The LCD Library in Arduino allows for controlling LCD DISPLAYS with the Arduino. This is based on the Hitachi HD44780 Chipset which is a dot MATRIX LCD (Liquid Crystal DISPLAY) Driver. It can be configured and used with 4-bit and 8-bit microcontrollers.

The correct CHOICE is (c) unsigned long

Easy explanation: The job of the pulseIn() function is to calculate the time difference (in MICROSECONDS) between two digital pulses. It gives the value as output in the form of an unsigned long VARIABLE. This is DONE so as to improve the accuracy of the function when MEASURING the time gap.

Correct answer is (c) YES, it can but only 2

To EXPLAIN: The digitalRead() FUNCTION is used to receive digital signals as input through the port and then process the DATA further. However, it can only distinguish between 5V (3.3V for some Arduino Boards) and 0V which correspond to the digital HIGH and the digital LOW signals RESPECTIVELY.

The correct option is (d) To dump or TRANSFER programs from the computer to the microcontroller

The explanation: The MOSI and MISO pins are a PART of the SPI (Serial Peripheral Interface) for transferring data over short distances. It is a FORM of Synchronous Serial Communication. These pins COMMIT hex data from the computer to the EEPROM and flash memory of the microcontroller.

Correct choice is (a) SIZEOF(a[0])

BEST explanation: When the first element of an array is invoked in the sizeof() function, if the array is a 2D array then it will give the number of elements PRESENT in the BREADTH of the matrix.

The CORRECT OPTION is (a) To enable ISR usage

To elaborate: The attachInterrupt() function ALLOWS us 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.

Correct answer is (b) Unsigned LONG

To explain: The millis() 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 milliseconds.

Correct ANSWER is (b) No

To elaborate: UART stands for Universal Asynchronous Receiver/Transmitter. This means all communication here is not governed by the presence of a clock UNLIKE the I2C and the SPI protocol which REQUIRE an EXTRA pin for performing serial communications.

Correct option is (a) Universal Asynchronous Receiver/Transmitter

To EXPLAIN I would say: The UART architecture is a very important part of SERIAL Communications. It is not a protocol like the I2C or SPI, but a physical circuit CONFIGURATION. Serial communication uses the UART architecture to send and receive the data serially from the COMPUTER.

Correct option is (b) Arduino MKRFOX1200

To explain I WOULD say: The SigFox Library ALLOWS the use of the SigFox transreceiver with the Arduino MKRFOX1200 BOARD. It uses UNB (Ultra Narrow Band) to interconnect remote devices. It’s a low energy device which falls in the category of LPWAN (Low Powered Wide Area Network).

The correct option is (c) The GSM Library

The BEST I can EXPLAIN: The GSM library on the Arduino helps the user to perform call, SMS, or even Internet Communications via the GSM Module. This library works in CONJUNCTION with the GSM Shield which USES a modem and AT commands to connect the Arduino to the GSM NETWORK.

Right choice is (d) To connect the ARDUINO to Ethernet

To explain: The Ethernet Library is USED to connect the Arduino to the internet via an Ethernet CONNECTION. This library is designed to be used with any Arduino Ethernet Shields or any other W5100, W5200, etc. based DEVICES.

The correct answer is (b) To use the previously generated “.o” files

The explanation is: During the compilation PROCESS, the Arduino compiler before compilation SEARCHES for previously generated “.o” files in the DIRECTORY, to make the compilation process faster in some cases. This reduces the redundancy of compiling the same PARTS of the code REPEATEDLY.

Right option is (d) 4

The best explanation: The shiftOut() FUNCTION requires 4 arguments; the PIN number to which the bit of DATA is to be sent, the toggle-pin which is to be turned HIGH or LOW once the data is done transferring, the order in which the bits are to be read (MSBFIRST or LSBFIRST), and the actual data who’s bits are to be shifted out.

Correct option is (d) To generate a square wave

Explanation: The tone() FUNCTION is used to generate a square wave of 50% duty cycle. It accepts a maximum of 3 arguments; the pin number, the frequency, and the duration of the wave. If no duration is specified then the wave is CONTINUED to be generated until the noTone() function is invoked WITHIN the code.

Right ANSWER is (a) Yes, it can

Easy explanation: Yes, the loop() function can replace the setup() function completely, theoretically, since both the loop() function and the setup() functions are custom predefined functions in the Arduino Environment. However, this would RESULT in more WORK from the developer’s END since he/she would have to find a way to make configuration code run only once.

Correct choice is (C) To map the Arduino Pin to the Interrupt pin

To explain I would SAY: The digitalPinToInterrupt() function translates the physical pin number on the arduino into the interrupt index. This works in almost all Arduino Boards and is usually used in conjunction with the attachInterrupt() function.

Right choice is (c) 16

To explain: Any number can be REPRESENTED in the FORM of a whole number or a floating-point number. If it must be represented as a whole number, then there are many options depending upon the size of the number in question. Here the short datatype takes up 16 bits of MEMORY. In other words, it can store NUMBERS between -32768 to 32767.

The correct answer is (b) 1

The best I can explain: The at() function returns a CHARACTER from the string given as input. It takes 1 ARGUMENT. It returns the character that is PRESENT in the string as specified by the argument. It can be used as “cout<

Correct choice is (a) Bitwise NOT

To explain I would say: The ~ operator is used to PERFORM a bitwise NOT operation on any TWO numbers which serve as the OPERANDS. It performs a NOT operation on each bit starting from the most SIGNIFICANT bit to the least significant bit.

Right CHOICE is (B) Ternary Operators WORK with 3 operands while unary operators work with 1 operand

The explanation is: The term “ternary” depicts three and the term “unary” depicts the term one. So therefore, ternary operators need 3 operands and unary operators use 1 operand.

Eg:-

The correct option is (b) Amplitude Modulation

Easy explanation: Any digital signal can be defined as a SERIES of 1’s and 0’s. These series may or may not be in a predefined pattern. This can make it very difficult for the receiver to be ABLE to decipher the signal. THUS, the digital coding techniques INVOLVE mostly converting a random pattern of 1’s and 0’s into a predefined pattern of a signal which the receiver can decipher easily. Here Amplitude Modulation Technique is an analog modulation technique.

Right answer is (c) SAMD Architecture

To explain: The Audio Frequency Meter Library only works on Arduino Boards having the SAMD Architecture, INCLUDING the Arduino Zero, MKRZero, etc. It allows for the sampling of an analog signal and finding out it’s frequency. Any analog PIN is SUPPORTED for this operation.

The correct ANSWER is (a) For managing dependencies

The EXPLANATION: The “.d” file format is used for managing and generating the dependency list for a program. A dependency is a supporting program that has the FUNCTIONALITY that is REQUIRED for the smooth and in times, the very execution of another program.

The correct option is (d) When the INTERRUPT is in effect

Easy explanation: The Interrupt Handler is an event by NATURE which, when raised, stops any code that is executing and first executes the code that is assigned to it, then RETURNS the control BACK to the normal EXECUTION.

Right answer is (c) ‘\0’

The explanation: The ‘\0’ when placed at the END of a string makes it a NULL terminated string which is simply a single DIMENSIONAL array of characters that are trailed by the ‘\0’ escape sequence. It is ALSO CALLED the ASCII NUL character.

The correct OPTION is (b) All pins EXCEPT pin 4

To explain: 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 Zero has ISR functionality enabled for all it’s pins except pin 4.

The correct choice is (b) 2

Explanation: The >= OPERATOR is a binary operator and it requires only 2 operands. The operator takes the two operands as INPUT which should be 2 numbers and then it outputs a Boolean True or a False DEPENDING UPON whether the operand 1 is GREATER than or equal to operand 2.