147 + Interview Questions in Interfacing Of Sensors in Arduino Page 1 InterviewSolution

1.	What is the purpose of the DATA pin in the rotary encoder?(a) To provide direction of motion(b) To power the module(c) To shut down the module(d) To provide analog reference voltageThe question was asked at a job interview.This interesting question is from Rotary Encoder topic in portion Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct answer is (a) To provide direction of motion The EXPLANATION: The ROTARY encoder has a CLK PIN and a DATA pin. The DATA pin gives out PULSES which vary in phase depending upon the direction of rotation of the rotary encoder which is determined by comparing it with the non-variable pulse train of the CLK pin.

Discussion

2.	What will happen if we supply a voltage of 25V to the Vcc of the MQ2 Gas Sensor?(a) Damage is caused(b) Module will shut down(c) Module will not respond for the time the voltage is applied(d) Module will function normallyThis question was addressed to me during an online interview.The origin of the question is MQ2 Gas Sensor Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct answer is (a) Damage is caused The explanation is: The MQ2 Gas Sensors are mostly built to work on a voltage of approximately 5V. Any voltage lower than that and the board will not be ABLE to power on, but however any voltage SIGNIFICANTLY above that and the board MAY SUFFER permanent damage.

Discussion

3.	What is the approximate self heating temperature of the LM35 Temperature Sensor Module?(a) 0.08°C(b) 0.91°C(c) 0.11°C(d) 1.23°CI had been asked this question in an internship interview.The question is from LM35 Temperature Sensor Module topic in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct choice is (a) 0.08°C The best explanation: The correct value of self HEATING under usual conditions for the LM35 Temperature Sensor MODULE is approximately 0.08°C. Self heating is the amount of heat that a particular electronic component generates while operating in a circuit due to INTERNAL resistances and IMPEDANCES to the flow of electrons through it.

Discussion

4.	If the PPM concentration of a gas that is being detected by the MQ2 Gas Sensor increases what will happen to its Analog Output pin?(a) Voltage Increases(b) Voltage Decreases(c) Voltage becomes 0(d) Voltage doesn’t changeThis question was addressed to me during an online exam.The query is from MQ2 Gas Sensor Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» CORRECT option is (a) Voltage Increases To elaborate: The MQ2 Gas SENSOR has two output pins, one is digital and one is analog. The analog PIN’s voltage is set so that it is directly proportional to the PPM value in the air subject to variation in calibration from the potentiometer, so as the PPM level rises so does the voltage in the analog output pin until it reaches 5V.

Discussion

5.	How many terminals does the MQ2 Gas Sensor have?(a) 1(b) 3(c) 2(d) 4The question was asked during an interview.My question is taken from MQ2 Gas Sensor Module in division Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct answer is (d) 4 To explain I would say: The MQ2 Gas Sensor has 4 terminals. These INCLUDE the Vcc for accepting positive VOLTAGE to power the sensor, GND for ground connections to COMPLETE the circuit and ACTIVATE the sensor, Dout which provides a digital output terminal and an Aout which provides the analog output terminal.

Discussion

6.	What is the formula for obtaining the temperature value in degrees centigrade from the LM35 Temperature Sensor while using an ADC?(a) °C=ADC/10mV(b) °C=ADC/100mV(c) °C=ADC/1mV(d) °C=ADC/120mVI have been asked this question in a national level competition.My question is based upon LM35 Temperature Sensor Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» CORRECT choice is (a) °C=ADC/10mV The best explanation: The correct formula for CONVERTING the voltage reading taken from the ADC into the correct DEGREES CENTIGRADE value of the temperature surrounding the sensor is °C=ADC/10mV. This is because 10mV is the scale factor of the LM35 Temperature Sensor Module.

Discussion

7.	Is there an interrupt pin on the RFID Module?(a) Yes(b) NoI got this question in an interview for internship.Query is from RFID Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct option is (a) Yes To elaborate: There is an interrupt PIN on the RFID Module which KEEPS the module alert to incoming connection requests from any RFID transmitter that approaches its maximum READ range so that it can THROW a subsequent software interrupt in order for the new transmitter to function in sync with the RECEIVER.

Discussion

8.	What is the maximum output voltage that the rotary encoder can put out on its DATA output pin?(a) 1V(b) 140V(c) 5V(d) 10VI got this question in an interview for internship.Enquiry is from Rotary Encoder topic in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» CORRECT option is (c) 5V Best explanation: The maximum output voltage of the DATA pin on the rotary ENCODER is 5V while the lowest is 0V. There is no voltage level in between them as the DATA out pin is a digital pin and can REPRESENT only 2 logic levels.

Discussion

9.	What is the full form of the abbreviation called PPM?(a) Parts Per Million(b) Parts Per Milligram(c) Parts Per Megagram(d) Parts Per MillilitreThis question was addressed to me in quiz.This question is from MQ2 Gas Sensor Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct answer is (a) Parts PER Million Easiest explanation: The correct full FORM of the PPM abbreviation is Parts per million. It is a way of measuring the concentration of a particular gas in the air, by using the RATIO of it and comparing it to others. For example: 1000 PPM of LPG means that if you count 1 million gas molecules within a closed space, 1000 of them would be LPG molecules while the rest would be other gases.

Discussion

10.	What is the sensitivity of the LM35 Temperature Sensor Module?(a) 10mV/°C(b) 1mV/°C(c) 23mV/°C(d) 12mV/°CThe question was asked during a job interview.Query is from LM35 Temperature Sensor Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right OPTION is (a) 10mV/°C For explanation: The SENSITIVITY per unit centigrade of the LM35 TEMPERATURE Sensor MODULE is the smallest degree CHANGE in temperature that corresponds to a change in the voltage reading on the sensor module.

Discussion

11.	What is the minimum temperature that the LM35 Temperature Sensor Module can read?(a) -11°C(b) -55°C(c) -10°C(d) 0°CThis question was posed to me in semester exam.This key question is from LM35 Temperature Sensor Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right answer is (b) -55°C For EXPLANATION I WOULD say: The minimum temperature that the LM35 Temperature Sensor Module can READ is -55°C, below which the module cannot generate sufficiently accurate order of voltage FLUCTUATIONS to denote a temperature value.

Discussion

12.	Does one need to calibrate the LM35 Temperature Sensor Module?(a) Yes(b) NoThis question was posed to me in an online interview.This interesting question is from LM35 Temperature Sensor Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct choice is (b) No The explanation: There is no need to calibrate the LM35 TEMPERATURE SENSOR MODULE since it is already pre-calibrated precisely to the degrees centigrade scale and this is ABSOLUTE and cannot be changed after the time of MANUFACTURE.

Discussion

13.	Is there an SDA pin on the RFID Module?(a) Yes(b) NoThis question was posed to me in my homework.This interesting question is from RFID Module topic in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct choice is (a) Yes Best EXPLANATION: The RFID Module has an SDA/SS/Rx PIN which, when the SPI Interface is enabled acts as a SIGNAL pin, when the I2C Interface is enabled acts as a Serial Data Pin, and in case of UART Mode Activation acts as a Serial Data INPUT pin.

Discussion

14.	If the PPM concentration of a gas that is being detected by the MQ2 Gas Sensor increases what will happen to its Digital Output pin?(a) Voltage Increases(b) Voltage Decreases(c) Voltage becomes 0(d) Voltage doesn’t changeThe question was asked during an online interview.This interesting question is from MQ2 Gas Sensor Module in division Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right answer is (d) VOLTAGE doesn’t change Explanation: The MQ2 Gas Sensor has two output pins, ONE is digital and one is analog. The digital PIN can only vary between two voltage levels which corresponds to 2 Logic Levels, 1 and 0 or 5V and 0V respectively. So if a gas is present then the digital output becomes 5V but cannot DETECT any kind of change in concentration of the gas.

Discussion

15.	Can the MQ2 Gas Sensor differentiate between two different gases with the same PPM?(a) Yes(b) NoI have been asked this question in an interview.I'm obligated to ask this question of MQ2 Gas Sensor Module topic in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct option is (b) No The best I can explain: The MQ2 Gas Sensor is not DESIGNED to tell which gases are present in the AIR surrounding the module. It can only tell what is the CONCENTRATION or PPM VALUE of a gas. The nature or name of the gas has to be known beforehand while using this sensor.

Discussion

16.	What is the maximum temperature value that the LM35 Temperature Sensor Module can read?(a) 100°C(b) 140°C(c) 150°C(d) 130°CI have been asked this question by my college director while I was bunking the class.I need to ask this question from LM35 Temperature Sensor Module topic in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct option is (c) 150°C The best I can explain: The maximum temperature that the LM35 Temperature Sensor Module can READ is 150°C, above which the module cannot GENERATE sufficient voltage in order to DENOTE a temperature VALUE accurately.

Discussion

17.	What is the use of the MQ2 Gas Sensor?(a) Object Identification(b) To provide 3G Connectivity(c) To measure presence of gas(d) To measure Wi-Fi strengthThe question was posed to me during an online exam.This intriguing question originated from MQ2 Gas Sensor Module topic in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct answer is (c) To measure presence of gas Explanation: The MQ2 Gas SENSOR is used to measure the DEGREE of presence of particular types of gases in the surrounding air. It can detect Methane, Butane, LPG and SMOKE quantities present in the air surrounding the sensor.

Discussion

18.	What is the role of the MISO pin in the RFID Module?(a) Master In Slave Out(b) Manage Internal Slave Output(c) Master Internal Search Optimization(d) Manage Input Slave OpI got this question during an online interview.The query is from RFID Module topic in portion Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct CHOICE is (a) Master In SLAVE Out To explain: The RFID Module’s MISO pin acts as Master In Slave Out while the SPI Interface is ACTIVATED, and as a serial clock when I2C Interface is enabled. However, when UART Mode is activated, it assumes the role of the Serial Data OUTPUT Pin.

Discussion

19.	What signal should be sent to the RESET pin of the Adafruit FONA 3G+GPS Breakout in order to perform a Hard Reset of the module?(a) 100ms LOW Signal(b) Continuous HIGH Signal(c) 100ms HIGH Signal(d) Continuous LOW SignalI got this question during an interview.My question is from Adafruit FONA 3G+GPS Breakout in division Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right CHOICE is (a) 100ms LOW Signal Explanation: The RESET Pin on theAdafruit FONA 3G+GPS Breakout should only be used when some software ISSUE has been created due to some configuration error. It COMPLETELY hard resets the board ERASING every manual configuration.

Discussion

20.	If the temperature would be 25°C then what would be the corresponding output on the LM35 Temperature Sensor?(a) 250mV(b) 200mV(c) 25V(d) 250VI had been asked this question by my college professor while I was bunking the class.My question is taken from LM35 Temperature Sensor Module topic in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right answer is (a) 250mV For explanation: The temperature SENSITIVITY of the LM35 Temperature Sensor Module is 10mV/°C which means that the value of the voltage output will INCREASE linearly with the increase in the surrounding temperature, or in other words it is linearly proportional. HENCE if the temperature OUTSIDE is 25°C then the output would be (10×25)mV or 250mV.

Discussion

21.	How many terminals does the rotary encoder have?(a) 1(b) 3(c) 5(d) 4This question was posed to me in examination.The above asked question is from Rotary Encoder in division Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» RIGHT option is (c) 5 To EXPLAIN I would say: The rotary encoder has 5 terminals which include the Vcc for power SUPPLY, the CLK for clock, DATA which provides us the output wave, and SWC which switches voltage to 0 and GND which is required for completing the circuit through the sensor and GROUNDING it.

Discussion

22.	How many LED indicators are present on the Adafruit FONA 3G+GPS Breakout?(a) 2(b) 1(c) 10(d) 4The question was asked in an online interview.This key question is from Adafruit FONA 3G+GPS Breakout in division Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct option is (d) 4 The best I can explain: There are 4 LED indicators present on theAdafruit FONA 3G+GPS Breakout. They include; NET for INDICATING the connection status and AT command acceptance, PWR for indicating when the module is booted, CHARGING which is usually ORANGE and indicates the status of charge for the on board LiPo Battery, and the Charged LED which indicates when the battery is fully charged.

Discussion

23.	What is the use of the rotary encoder?(a) To measure RPM or speed(b) To provide 3G Connectivity(c) To measure presence of gas(d) To measure Wi-Fi strengthI have been asked this question in my homework.This question is from Rotary Encoder topic in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right answer is (a) To measure RPM or speed To explain: The rotary encoder is used to measure the RPM or speed or any other such motion and angular velocity related PARAMETERS of any ROBOTIC SYSTEM or any other system in GENERAL. It provides a series of ticks which provide us with the necessary information to DECODE that into our required values.

Discussion

24.	What will happen if we supply a voltage of 250V to the Vcc of the LM35 Temperature Sensor Module?(a) Damage is caused(b) Module will shut down(c) Module will not respond for the time the voltage is applied(d) Module will function normallyThis question was addressed to me during a job interview.The doubt is from LM35 Temperature Sensor Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right OPTION is (a) Damage is caused Easiest EXPLANATION: The LM35 Temperature SENSOR Modules are mostly built to work on a voltage of approximately 4V to 30V. Any voltage lower than that and the board will not be able to POWER on, but however any voltage significantly above that and the board may suffer permanent damage.

Discussion

25.	How many terminals does the LM35 Temperature Sensor Module have?(a) 1(b) 3(c) 2(d) 4The question was posed to me in semester exam.This is a very interesting question from LM35 Temperature Sensor Module topic in portion Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct answer is (b) 3 To ELABORATE: The LM35 Temperature Sensor Module has 3 terminals which correspond to the GND or ground, the VCC which acts as VOLTAGE INPUT, and OUT which puts out the OUTPUT voltage of the sensor corresponding to the temperature.

Discussion

26.	What is the maximum data rate of the RFID Module?(a) 11 Mbps(b) 1 Kbps(c) 10 Mbps(d) 11 GbpsI have been asked this question by my college professor while I was bunking the class.I'd like to ask this question from RFID Module in division Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct ANSWER is (c) 10 MBPS Explanation: The maximum data RATE of any given DEVICE is the ability of that given device to transfer as many bits of information from one location to another in unit time. Here, the maximum data rate of the RFID Module is 10 Mbps, which means that the module can transfer a maximum of 10 Megabytes of data in 1 second.

Discussion

27.	What is the use of the LM35 Temperature Sensor Module?(a) Object Identification(b) To provide 3G Connectivity(c) To measure temperature(d) To measure Wi-Fi strengthI have been asked this question by my school principal while I was bunking the class.My enquiry is from LM35 Temperature Sensor Module in division Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The CORRECT answer is (C) To measure temperature Easy EXPLANATION: The LM35 Temperature sensor module is used for measuring the temperature in the immediate surroundings of the sensor. The OUTPUT of the sensor is an analog voltage which is proportional to the Celsius temperature SCALE.

Discussion

28.	What is the purpose of the CLK pin in the rotary encoder?(a) To provide pulse reference(b) To power the module(c) To shut down the module(d) To provide analog reference voltageI have been asked this question in my homework.Origin of the question is Rotary Encoder in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct option is (a) To PROVIDE PULSE reference For explanation: The rotary encoder has a CLK pin and a DATA pin. The DATA pin gives out PULSES which vary in PHASE depending upon the direction of rotation of the rotary encoder. However we cannot determine these variations until we compare the wave pattern with ANOTHER steady non-variable pulse train. The CLK pin provides exactly that.

Discussion

29.	Does the MQ2 Gas Sensor have a fixed sensitivity?(a) Yes(b) NoI have been asked this question in an interview for internship.Asked question is from MQ2 Gas Sensor Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct choice is (b) No To explain I would say: The SENSITIVITY of any sensor is its ability to detect the smallest degree of change in the measuring medium that generates an accurate output in the sensor’s TERMINALS. The sensitivity of the MQ2 Gas Sensor is not fixed in itself and can be varied using a potentiometer.

Discussion

30.	Till what voltage are the logic pins on the RFID Module resistant to?(a) 5V(b) 3.3V(c) 2V(d) 12VThis question was posed to me during a job interview.I want to ask this question from RFID Module topic in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right answer is (a) 5V Explanation: The logic pins on the RFID Module are RESISTANT up to 5V despite having an OPERATIONAL range of 2.5V to 3.3V. This means that one does not NEED to connect any logic level CONVERTER circuit in between the RFID Module and any other Arduino Microcontrollers which WORK on 5V.

Discussion

31.	What is the maximum read range of the RFID Module?(a) 2 cm(b) 1 cm(c) 10 cm(d) 5 cmThis question was posed to me during a job interview.The origin of the question is RFID Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right choice is (d) 5 cm Explanation: The maximum read range of an RFID MODULE is the maximum distance in space that the RECEIVER module can read the signal sent by the transmitter module. In order for proper working of the module during OPERATION, it is advised that both the MODULES are kept within the read range for accurate performance.

Discussion

32.	What is the use of the RTSin pin on theAdafruit FONA 3G+GPS Breakout?(a) Right Turn Pin(b) Hardware Control Pin(c) Software Control Pin(d) Residue Transmitter PinThe question was asked during an internship interview.I want to ask this question from Adafruit FONA 3G+GPS Breakout in division Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct choice is (b) HARDWARE CONTROL Pin Explanation: TheAdafruit FONA 3G+GPS BREAKOUT has the RTSin pin to control flow of transfer from the board to the micro-controller CONNECTED to it, and vice versa. The user can decide to EITHER turn ON the flow or turn OFF the flow.

Discussion

33.	What is the name of the mesh surrounding the MQ2 Gas Sensor?(a) Anti-Heat Mesh(b) Anti-Explosion Mesh(c) Anti-Air Mesh(d) Filtration MeshThis question was addressed to me in semester exam.My query is from MQ2 Gas Sensor Module in portion Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct choice is (b) Anti-Explosion Mesh To explain: The MQ2 Gas Sensor is surrounded by a mesh called Anti-Explosion Mesh. This protects the ACTUAL sensor inside from combusting as it REMAINS in a heated condition during NORMAL operation and coming into CONTACT with gases like methane or butane or LPG may IGNITE the gas and cause dangerous accidents.

Discussion

34.	Do the SPK + and – pins on the Adafruit FONA 3G+GPS Breakout have DC blocking capacitors ?(a) Yes(b) NoThis question was addressed to me in homework.Query is from Adafruit FONA 3G+GPS Breakout topic in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The CORRECT answer is (a) Yes To explain: The SPK + and – PINS on theAdafruit FONA 3G+GPS Breakout are used to connect to any 8 Ohm speakers, the two pins are DIFFERENTIAL so they do not need to be connected to any DC blocking CAPACITORS, however they should not be used to connect to any stereo powered speakers.

Discussion

35.	What will happen if we supply a voltage of 25V to the Vcc of the rotary encoder?(a) Damage is caused(b) Module will shut down(c) Module will not respond for the time the voltage is applied(d) Module will function normallyI had been asked this question in an interview.Question is from Rotary Encoder in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The CORRECT OPTION is (a) Damage is caused To elaborate: The rotary encoders are MOSTLY built to work on a voltage of APPROXIMATELY 3.3V to 5V. Any voltage LOWER than that and the board will not be able to power on, but however any voltage significantly above that and the board may suffer permanent damage.

Discussion

36.	What is the full form of the RI pin on the Adafruit FONA 3G+GPS Breakout?(a) Ring Indicator(b) Right Indicator(c) Right Impersonation(d) Rig IndicatorThis question was posed to me by my college director while I was bunking the class.My question is taken from Adafruit FONA 3G+GPS Breakout in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» RIGHT choice is (a) Ring Indicator Best explanation: The Adafruit FONA 3G+GPS Breakout has an RI pin which acts as a interrupt out pin for it. When a call is RECEIVED on the module this pin becomes LOW, and is HIGH by DEFAULT. Furthermore, it can also be USED as an indicator for SMS.

Discussion

37.	What is the maximum output voltage that the MQ2 Gas Sensor can put out on its analog output pin?(a) 1V(b) 140V(c) 5V(d) 10VThis question was addressed to me in my homework.I would like to ask this question from MQ2 Gas Sensor Module topic in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right option is (c) 5V The explanation is: The maximum output voltage of the MQ2 Gas Sensor is 5V. Any PPM concentrations within that LIMIT can be detected with ACCURACY by the sensor. However, ONE can detect higher or lower PPM concentrations to a certain DEGREE by adjusting the potentiometer.

Discussion

38.	What will happen if we supply a voltage of 25V to the Vcc of the RFID Module?(a) Damage is caused(b) Module will shut down(c) Module will not respond for the time the voltage is applied(d) Module will function normallyThe question was posed to me in an interview for internship.The doubt is from RFID Module in division Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct choice is (a) DAMAGE is caused Explanation: The RFID Modules are mostly built to work on a voltage of APPROXIMATELY 3.3V. Any voltage lower than that and the BOARD will not be able to power on, but however any voltage significantly above that and the board may suffer PERMANENT damage.

Discussion

39.	What is the minimum working current internally in the RFID Module?(a) 12 mA(b) 13 mA(c) 10 mA(d) 1 mAI have been asked this question during an interview for a job.This question is from RFID Module topic in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct choice is (b) 13 mA Explanation: The internal working current inside the RFID MODULE ranges between 13 mA and 26 mA approximately. If there is a power SURGE in any PORTION of the module, it can mean that there is a faulty COMPONENT which can be DANGEROUS for the entire module as a whole.

Discussion

40.	What is the use of the RFID Module?(a) Object Identification(b) To provide 3G Connectivity(c) To measure temperature(d) To measure Wi-Fi strengthI have been asked this question in unit test.The question is from RFID Module in portion Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» CORRECT option is (a) Object Identification To EXPLAIN: The RFID Module is primarily used for object identification and tracking. It’s abbreviation stands for RADIO Frequency Identification Module. It’s WORKING is mostly wireless and USES electromagnetic fields.

Discussion

41.	Which frequency does the RFID Module operate in?(a) 12.98 MHz(b) 14.67 MHz(c) 19.56 MHz(d) 13.56 MHzThis question was posed to me during an interview.The doubt is from RFID Module topic in division Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct OPTION is (d) 13.56 MHz Explanation: The RFID MODULE operates in the 13.56 MHz FREQUENCY SINCE it is the universal unregulated frequency for all scientific and medical research purposes. It was set as the standard international frequency to be followed by all, since it does not interfere significantly with the environment.

Discussion

42.	What is the use of the X and Y Addresses of the RAM for Display Control?(a) Rows and Columns(b) Rows(c) Columns(d) PixelsThe question was asked during an interview.The question is from OLED Display Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» RIGHT option is (a) Rows and Columns For explanation I WOULD say: The X and Y ADDRESSES of the RAM in the Display Control unit of the Module are used for referring to the row and column position of a particular pixel on the MONITOR of the module.

Discussion

43.	What will happen if we supply a voltage of 25V to the Vcc of the Adafruit FONA 3G+GPS Breakout?(a) Damage is caused(b) Module will shut down(c) Module will not respond for the time the voltage is applied(d) Module will function normallyI had been asked this question during an internship interview.This intriguing question originated from Adafruit FONA 3G+GPS Breakout topic in portion Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct option is (a) DAMAGE is caused To EXPLAIN I WOULD SAY: The Adafruit FONA 3G+GPS Breakoutare mostly BUILT to work on a voltage of approximately 5V. Any voltage lower than that and the board will not be able to power on, but however any voltage significantly above that and the board may suffer permanent damage.

Discussion

44.	What is the use of the Vcc1 pin?(a) Input(b) Output(c) Activation(d) Power inputI have been asked this question in a national level competition.Asked question is from Motor Driver (L293D) and Motors topic in division Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct choice is (d) POWER input To EXPLAIN I would SAY: The Vcc1 pin is used for powering the internal IC components. It ACCEPTS a maximum of 5V approximately. This should not be confused with the Vcc2 pin which powers the MOTORS as that could lead to the blowout of the IC.

Discussion

45.	What is the type of output given by the DC Relay Module?(a) Analog Signal(b) AC Signal(c) DC Signal(d) Hybrid SignalI got this question in examination.This intriguing question comes from Relay (Dual Channel) Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The CORRECT answer is (c) DC Signal Explanation: The RELAY MODULE can SWITCH current flow depending upon the rating ofit. If the Relay Module has been rated for DC Usage then it should not be used for AC Circuits and vice-versa.

Discussion

46.	What kind of device is the Relay Module?(a) Passive Sensor(b) Active Sensor(c) Radio Device(d) Switching DeviceThe question was asked in quiz.Query is from Relay (Dual Channel) Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct choice is (d) Switching Device Explanation: The Relay Module is a switching device since it’s primary function is to switch or CHANGE the DIRECTION of flow of current or STOP it altogether. This way it controls the WORKING of any GIVEN circuit.

Discussion

47.	What is the use of the AD0 pin?(a) I2C Slave Address LSB Pin(b) SPI Master Address MSB Pin(c) UART Slave Address LSB Pin(d) UART Master Address LSB PinI have been asked this question in my homework.My enquiry is from MPU6050 Sensor Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right option is (a) I2C Slave Address LSB PIN Explanation: The AD0 pin is the I2C Slave Address LSB pin on the MPU 6050. This is 0TH bit in 7-bit slave address of device. If connected to VCC then it is read as LOGICAL HIGH and slave address changes.

Discussion

48.	Which of the formulae give us the value of acceleration for the x-axis in the ADXL-335?(a) Axout = (((Value * Vref) / 1024) – 1.65) / 0.330(b) Axout = (((Value * Vref) / 1024) – 1.65) / 2000(c) Axout = (((Value * Vref) / 1024) – 1.65) / 330(d) Axout = (((Value * Vref) / 1024) – 1.65) / 0.12I have been asked this question during an internship interview.The doubt is from ADXL335 Accelerometer Sensor in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Right choice is (a) Axout = (((Value * VREF) / 1024) – 1.65) / 0.330 To explain I would say: (((Value * Vref) / 1024) – 1.65) / 0.330 gives the correct value of acceleration along any axis of the accelerometer module. HOWEVER, in order to make the EQUATION work, we would need to plug in the values of the X-axis, Y-axis, and Z-axis SEPARATELY in 3 different variables to obtain the value of acceleration along each individual axis.

Discussion

49.	What is the use of the VLCD?(a) Temperature Control(b) Heat Generation(c) Shutting down the LCD(d) Starting up the LCDThis question was posed to me by my school teacher while I was bunking the class.Question is from Nokia 5110 Graphical Display Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» The correct choice is (a) Temperature Control Explanation: The LCD NEEDS a particular OPTIMUM temperature to be able to function properly, so we have the temperature control REGISTERS TC0 and TC1 for that purpose so that the VLCD or the LCD controlling Voltage is regulated to the right temperature for maximum IMAGE contrast on the display MODULE.

Discussion

50.	What is the use of the IR Sensor?(a) Object Detection(b) Humidity Detection(c) Image Processing(d) GPSI had been asked this question in an online quiz.My question is based upon IR Sensor topic in section Interfacing of Sensors, Actuators, and Other Modules of Arduino
Answer» Correct option is (a) Object Detection For EXPLANATION I would SAY: The IR Sensor is used for calculating the distance between the sensor and the object. It is mostly used for calculating the acceleration, VELOCITY and position of the sensor attached to the device. It BASICALLY has two terminals which emit an IR Signal and receive the emitted IR Signal. The time difference between these two gives us the required DATA for such calculations.

Discussion

Explore topic-wise InterviewSolutions in .

How many terminals does the MQ2 Gas Sensor have?(a) 1(b) 3(c) 2(d) 4The question was asked during an interview.My question is taken from MQ2 Gas Sensor Module in division Interfacing of Sensors, Actuators, and Other Modules of Arduino

Is there an interrupt pin on the RFID Module?(a) Yes(b) NoI got this question in an interview for internship.Query is from RFID Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino

What is the maximum output voltage that the rotary encoder can put out on its DATA output pin?(a) 1V(b) 140V(c) 5V(d) 10VI got this question in an interview for internship.Enquiry is from Rotary Encoder topic in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino

What is the sensitivity of the LM35 Temperature Sensor Module?(a) 10mV/°C(b) 1mV/°C(c) 23mV/°C(d) 12mV/°CThe question was asked during a job interview.Query is from LM35 Temperature Sensor Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino

What is the minimum temperature that the LM35 Temperature Sensor Module can read?(a) -11°C(b) -55°C(c) -10°C(d) 0°CThis question was posed to me in semester exam.This key question is from LM35 Temperature Sensor Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino

Does one need to calibrate the LM35 Temperature Sensor Module?(a) Yes(b) NoThis question was posed to me in an online interview.This interesting question is from LM35 Temperature Sensor Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino

Is there an SDA pin on the RFID Module?(a) Yes(b) NoThis question was posed to me in my homework.This interesting question is from RFID Module topic in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino

Can the MQ2 Gas Sensor differentiate between two different gases with the same PPM?(a) Yes(b) NoI have been asked this question in an interview.I'm obligated to ask this question of MQ2 Gas Sensor Module topic in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino

How many terminals does the rotary encoder have?(a) 1(b) 3(c) 5(d) 4This question was posed to me in examination.The above asked question is from Rotary Encoder in division Interfacing of Sensors, Actuators, and Other Modules of Arduino

How many LED indicators are present on the Adafruit FONA 3G+GPS Breakout?(a) 2(b) 1(c) 10(d) 4The question was asked in an online interview.This key question is from Adafruit FONA 3G+GPS Breakout in division Interfacing of Sensors, Actuators, and Other Modules of Arduino

How many terminals does the LM35 Temperature Sensor Module have?(a) 1(b) 3(c) 2(d) 4The question was posed to me in semester exam.This is a very interesting question from LM35 Temperature Sensor Module topic in portion Interfacing of Sensors, Actuators, and Other Modules of Arduino

Does the MQ2 Gas Sensor have a fixed sensitivity?(a) Yes(b) NoI have been asked this question in an interview for internship.Asked question is from MQ2 Gas Sensor Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino

Till what voltage are the logic pins on the RFID Module resistant to?(a) 5V(b) 3.3V(c) 2V(d) 12VThis question was posed to me during a job interview.I want to ask this question from RFID Module topic in section Interfacing of Sensors, Actuators, and Other Modules of Arduino

What is the maximum read range of the RFID Module?(a) 2 cm(b) 1 cm(c) 10 cm(d) 5 cmThis question was posed to me during a job interview.The origin of the question is RFID Module in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino

Do the SPK + and – pins on the Adafruit FONA 3G+GPS Breakout have DC blocking capacitors ?(a) Yes(b) NoThis question was addressed to me in homework.Query is from Adafruit FONA 3G+GPS Breakout topic in chapter Interfacing of Sensors, Actuators, and Other Modules of Arduino

What is the minimum working current internally in the RFID Module?(a) 12 mA(b) 13 mA(c) 10 mA(d) 1 mAI have been asked this question during an interview for a job.This question is from RFID Module topic in section Interfacing of Sensors, Actuators, and Other Modules of Arduino

What is the use of the RFID Module?(a) Object Identification(b) To provide 3G Connectivity(c) To measure temperature(d) To measure Wi-Fi strengthI have been asked this question in unit test.The question is from RFID Module in portion Interfacing of Sensors, Actuators, and Other Modules of Arduino

Which frequency does the RFID Module operate in?(a) 12.98 MHz(b) 14.67 MHz(c) 19.56 MHz(d) 13.56 MHzThis question was posed to me during an interview.The doubt is from RFID Module topic in division Interfacing of Sensors, Actuators, and Other Modules of Arduino

What is the use of the X and Y Addresses of the RAM for Display Control?(a) Rows and Columns(b) Rows(c) Columns(d) PixelsThe question was asked during an interview.The question is from OLED Display Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino

What is the use of the Vcc1 pin?(a) Input(b) Output(c) Activation(d) Power inputI have been asked this question in a national level competition.Asked question is from Motor Driver (L293D) and Motors topic in division Interfacing of Sensors, Actuators, and Other Modules of Arduino

What is the type of output given by the DC Relay Module?(a) Analog Signal(b) AC Signal(c) DC Signal(d) Hybrid SignalI got this question in examination.This intriguing question comes from Relay (Dual Channel) Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino

What kind of device is the Relay Module?(a) Passive Sensor(b) Active Sensor(c) Radio Device(d) Switching DeviceThe question was asked in quiz.Query is from Relay (Dual Channel) Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino

What is the use of the IR Sensor?(a) Object Detection(b) Humidity Detection(c) Image Processing(d) GPSI had been asked this question in an online quiz.My question is based upon IR Sensor topic in section Interfacing of Sensors, Actuators, and Other Modules of Arduino