AVR Microcontroller

I/O Port Programming and Addressing Modes

1. In AVR, which registers are there for the I/O programming of ports?

a) PORT

b) PIN

c) DDR

d) All of the mentioned

Answer: All of the mentioned

2. The data will not go from the port registers to the pin unless:

a) DDR register of that port is set to 0

b) PORT register of that port is set to 1

c) DDR register of that port is set to 1

d) PORT register of that port is set to 0

Answer: DDR register of that port is set to 1

3. On reset DDR registers of all ports are set to:

a) 0

b) 1

c) None of the mentioned

d) 0 & 1

Answer: 0

4. Which of the following statements are correct?

a) PIN register of a port is used to bring data into CPU from pins

b) PORT register is used to send data out to pins

c) DDR register is used to control the direction of a port

d) All of the mentioned

Answer: All of the mentioned

5. In the AVR family, all I/O ports have 8 pins?

a) true

b) false

c) none of the mentioned

d) can’t be determined

Answer: false

6. Which of the following is not a single bit instruction in AVR?

a) SBI

b) PORT

c) CBI

d) All of the mentioned

Answer: PORT

7. Which of the following is correct about the SBIS instruction?

a) it is used to monitor status of bit in I/O register

b) it is a byte oriented instruction

c) It is a 4 byte instruction

d) all of the mentioned

Answer: it is used to monitor status of bit in I/O register

8. Instruction CBI PORTB,1 means

a) clearing the PORTB register

b) clearing the first bit of the PORTB register

c) setting the PORTB register

d) setting the first bit of the PORTB register

Answer: clearing the first bit of the PORTB register

9. Which of the following instruction can be used to toggle a bit of the PORT?

a) SBI

b) CBI

c) SBI & CBI

d) None of the mentioned

Answer: SBI & CBI

10. What is the main function of the SBIC instruction?

a) it is used to clear a particular bit of a port

b) it is used to jump unconditionally

c) it is used to skip the instruction if a particular bit of a port is zero

d) none of the mentioned

Answer: it is used to skip the instruction if a particular bit of a port is zero

Arithmetic and Logic Instructions

1. In AVR microcontrollers, ADD instruction affects the status of which of the following bits of a status register?

a) Z

b) C

c) N

d) All of the mentioned

Answer: All of the mentioned

2. ADC instruction is used for?

a) addition of two 16 bit numbers

b) analog to digital conversion

c) automatic digital control

d) none of the mentioned

Answer: addition of two 16 bit numbers

3. AVR supports which of the following mentioned subtraction instructions?

a) SUB

b) SBC

c) SUBI

d) All of the mentioned

Answer: All of the mentioned

4. What steps are involved when we subtract two numbers present at two different locations?

a) take the two’s complement of the subtrahend

b) add it to the minuend

c) invert the carry

d) all of the mentioned

Answer: all of the mentioned

5. In executing subtraction based instructions, state the role of the C flag?

a) if C=1, the result is negative

b) if C=1, the result is positive

c) none of the mentioned

d) all of the mentioned

Answer: if C=1, the result is negative

6. Which of the following is correct about the MUL instruction?

a) it is a byte-by-byte multiplication instruction

b) the product is stored in two registers R1 and R0

c) all of the mentioned

d) none of the mentioned

Answer: all of the mentioned

7. In AVR, when is the V flag set?

a) there is a carry from D7 bit

b) there is a carry from D6 to D7 bit

c) when carry is generated only from D6 to D7 or carry is generated only from D7

d) none of the mentioned

Answer: when carry is generated only from D6 to D7 or carry is generated only from D7

8. To set the bits of a register R1 to 1, we must OR the contents of the register with?

a) 00H

b) 11H

c) FFH

d) 0FH

Answer: FFH

9. CP instruction alters the value of the register?

a) true

b) false

c) none of the mentioned

d) can’t be said

Answer: false

10. What is right about the ROR instruction?

a) it rotates the contents of the register left to right

b) it rotates the contents of the register from right to left

c) it rotates the contents of the register from left to right through carry

d) it rotates the contents of the register from right to left through carry

Answer: it rotates the contents of the register from left to right through carry

Timer Programming

1. In AVR, which of the following registers are not used for programming timers?

a) TCNT

b) TCON

c) TIFR

d) None of the mentioned

Answer: TCON

2. What is the use of the prescalar in the operation of the timer?

a) for fast calculations

b) for increasing the time delay given by the timer by decreasing its frequency of operation

c) for removing the concept the reloading of count

d) for easy counter operations

Answer: for increasing the time delay given by the timer by decreasing its frequency of operation

3. What modes are generally used in the operation of the timer0?

a) Normal mode

b) CTC mode

c) PWM mode

d) All of the mentioned

Answer: All of the mentioned

4. Timer 0 can act as a counter ____________

a) if the CS02-CS00 are 110 or 111

b) if the FOC0 bit is set to 110

c) none of the mentioned

d) all of the mentioned

Answer: if the CS02-CS00 are 110 or 111

5. Which of the timer can operate in the 16 bit condition?

a) timer0

b) timer1

c) timer2

d) all of the mentioned

Answer: timer1

6. Which of the following will generate the maximum time delay?

a) f/2

b) f/4

c) f/16

d) f/32

Answer: f/32

7. What is the difference in the operation of a normal and a CTC mode of a timer?

a) in CTC mode PWM is used

b) here serial timer is monitored

c) in CTC mode, timer counts up until contents of TCNT register becomes equal to the contents of OCR

d) none of the mentioned

Answer: in CTC mode, timer counts up until contents of TCNT register becomes equal to the contents of OCR

8. We can count the pulses on the positive or the negative edge triggered pulse of the clock?

a) true

b) false

c) can’t be determined

d) depends on the circumstances

Answer: true

9. Which pin is used for the input clock of the counter0?

a) PORTB.0

b) PORTB.1

c) PORTB.2

d) PORTB.3

Answer: PORTB.0

10. Which resource provides the clock pulse to AVR timers if CS02-00=6?

a) internal clock of the AVR

b) external clock of the AVR

c) none of the mentioned

d) all of the mentioned

Answer: external clock of the AVR

Interrupt Programming

1. On reset, what are the contents of the SREG register?

a) 00h

b) ffh

c) 1fh

d) 11h

Answer: 00h

2. TIMSK register is used for?

a) knowing the status of the timer count

b) used for masking the interrupts flags of the Timer0, Timer1 and Timer2

c) it is used for enabling all the timer interrupts

d) it is used for resetting the value of the interrupts

Answer: used for masking the interrupts flags of the Timer0, Timer1 and Timer2

3. Why RETI instruction be the last instruction of ISR?

a) because it returns with carry

b) because it returns to the main program with all the flags of the SREG raised

c) because it returns to the main program where interrupt is generated and set the global interrupt enable bit in SREG

d) none of the mentioned

Answer: because it returns to the main program where interrupt is generated and set the global interrupt enable bit in SREG

4. In AVR what is the ISR address for an external hardware interrupt?

a) 0002h

b) 0004h

c) 0006h

d) all of the mentioned

Answer: all of the mentioned

5. What is the address in the interrupt service routine assigned for the timer0 overflow flag?

a) 0012h

b) 000Ah

c) 0016h

d) all of the mentioned

Answer: 0016h

6. Is the same address is assigned for the timer0 and timer1 overflow flag in the interrupt vector table of the interrupts?

a) true

b) false

c) can’t be determined

d) depends on the situation

Answer: false

7. External hardware interrupts are assigned to which pins of the atmega32?

a) PORTD.2

b) PORTD.3

c) PORTB.2

d) All of the mentioned

Answer: All of the mentioned

8. Which register is responsible for handling all the external hardware interrupts?

a) TIMSK

b) GICR

c) MCUCR

d) IVCE

Answer: GICR

9. By default, INT0-INT2 interrupts are?

a) edge triggered

b) level triggered

c) all of the mentioned

d) none of the mentioned

Answer: level triggered

10. What will happen in that condition, if an interrupt occurs while the microcontroller is serving any other interrupt?

a) both the interrupts will be handled simultaneously

b) the interrupt which is being done first will be served first

c) the interrupt that is more priority in the interrupt vector table will be served first

d) the interrupt having low priority in the interrupt vector table will be served first

Answer: the interrupt that is more priority in the interrupt vector table will be served first

Serial Port Communication

1. What actually are the DB9, DB25 ports available in our computers?

a) they are connectors used to transfer data either serially or parallelly

b) they are the RS232 connectors used to connect two incompatible devices

c) they are the TTL logic connector pins used for communication

d) they are just data transfer pins used to transfer the data

Answer: they are the RS232 connectors used to connect two incompatible devices

2. What does RI handshaking signal refer to according to the RS232 logic?

a) if this logic is high then a receive interrupt is generated

b) this pin is high during transmission

c) this pin is high during a reception in order to tell that the device is busy at this particular time

d) none of the mentioned

Answer: this pin is high during a reception in order to tell that the device is busy at this particular time

3. What is the major difference between a MAX232 and a MAX233 device?

a) one has one serial port other has two

b) one has inbuilt UART other doesn’t have that

c) one needs some additional circuitry to operate while the other doesn’t have that

d) one is used just for transmission while the other is used for both transmission as well as reception

Answer: one needs some additional circuitry to operate while the other doesn’t have that

4. Which of the following is correct about the baud rate during serial transmission?

a) it tells us about the speed at which the transmission is going to place

b) it tells us about the number of bits transferred during a second

c) none of the mentioned

d) all of the mentioned

Answer: all of the mentioned

5. With fosc=8 MHz, what will the count that has to filled in the UBRR register to account for the 9600 baud rate?

a) 67H

b) CEH

c) 33H

d) 34H

Answer: 33H

6. The USART in AVR based microcontrollers operate at which of the following modes?

a) double speed asynchronous mode

b) master synchronous

c) slave synchronous

d) all of the mentioned

Answer: all of the mentioned

7. Which bit of the UCSRA is used for doubling the baud rate of the transmission?

a) DOR

b) PE

c) U2X

d) MPCM

Answer: U2X

8. What is the use of the PE and the FE bits of the UCSRA register?

a) they are used for keeping a check at the speed of transmission and reception

b) they are used for keeping a check at the data bits to be transferred

c) they are used to keep the transmission error free

d) they are used as extra redundant bits with no use

Answer: they are used to keep the transmission error free

9. Which of the following bits are used for setting the data frame size?

a) UCSZ0

b) U2X

c) DOR

d) MPCM

Answer: UCSZ0

10. Which of the following parameters should the transmitter and the receiver agree upon before starting a serial transmission?

a) baud rate

b) frame size

c) stop bit

d) all of the mentioned

Answer: all of the mentioned

Interfacing with 8255

1. The 8255 is a ______ chip.

a) Input/Output

b) Analog to Digital

c) Digital to analog

d) None of the mentioned

Answer: Input/Output

2. Which pins of a microcontroller are directly connected with 8255?

a) RD

b) WR

c) D0-D7

d) All of the mentioned

Answer: All of the mentioned

3. Find the control word for PA= out, PB= in, PCL=out, PCH=out (Mode0)?

a) 0x02H

b) 0x82H

c) 0x83H

d) 0x03H

Answer: 0x82H

4. Which pins are used to select the ports and the control register?

a) CS

b) A1

c) A0

d) All of the mentioned

Answer: All of the mentioned

5. What is the value of the control register when RESET button is set to zero?

a) 0x00H

b) 0xFFH

c) 0x11H

d) value remains the same

Answer: value remains the same

6. Why MOVX instruction is being used to access the ports of the 8255?

a) because 8255 is connecting a microcontroller in memory mapped I/O configuration

b) because 8255 is used to access the external communication

c) because 8255 is used to access the data transfer

d) because 8255 is used to access the interfacing of LCD, motor etc

Answer: because 8255 is connecting a microcontroller in memory mapped I/O configuration

7. What is correct about the BSR mode from below?

a) In BSR mode, only the individual bits of PORT A can be programmed

b) In BSR mode, only the individual bits of PORT B can be programmed

c) In BSR mode, only the individual bits of PORT C can be programmed

d) none of the mentioned

Answer: In BSR mode, only the individual bits of PORT C can be programmed

8. How many pins of the 8255 can be used as the I/O ports?

a) 8

b) 16

c) 24

d) 32

Answer: 24

9. 8255 is a ____ pin IC.

a) 16

b) 8

c) 40

d) 60

Answer: 40

10. 8255 has handshaking capability?

a) yes

b) no

c) cant be said

d) depends on the conditions

Answer: yes

11. The 8255 can be programmed in any of the __________

a) 2 modes

b) 3 modes

c) 4 modes

d) 5 modes

Answer: 4 modes

Interfacing with RTC

1. RTC is used for __________

a) conversion

b) communication

c) real time and clock measurement

d) memory management

Answer: real time and clock measurement

2. RTC chips use ______ to compute time, date when the power is off.

a) ac supply

b) generators

c) rectifiers

d) battery

Answer: battery

3. DS12887 is known for as a ________

a) Communication device

b) Good battery device

c) RTC chip

d) All of the mentioned

Answer: RTC chip

4. DS1307 is a parallel RTC with I2C bus.

a) true

b) false

c) cant be said

d) depends on the conditions

Answer: false

5. DS1307 is a _______ pin IC and operates on _______ clock frequency.

a) 16, 8Mhz

b) 8, 16Mhz

c) 16, 32Mhz

d) 8, 32Khz

Answer: 8, 32Khz

6. Vbat requires a positive signal of

a) 3V

b) 5V

c) 9V

d) 12V

Answer: 3V

7. In DS1307, which out of the following is correct about the SQW pin?

a) input pin

b) output pin

c) i/o pin

d) none of the mentioned

Answer: output pin

8. DS1307 has a total of _______ bytes of RAM space.

a) 32

b) 64

c) 128

d) 256

Answer: 64

9. DS1307 control register has an address of _________

a) 00H

b) 03H

c) 07H

d) 10H

Answer: 07H

10. What does the CH bit of the DS1307 demonstrate?

a) clock high

b) clock halt

c) clear high

d) clear halt

Answer: clock halt

Interfacing with Motors

1. Why are relays used for driving the motors?

a) they can be used as switch as well as they provide isolation

b) they increase the current capability required by the motors

c) they are used to reduce the back emf from the motors

d) all of the mentioned

Answer: they can be used as switch as well as they provide isolation

2. Why are ULN2803 normally used between the microcontrollers and the relays?

a) for switching purposes

b) for increasing the current capability required by a relay

c) for increasing the voltage capability required by a relay

d) all of the mentioned

Answer: for increasing the current capability required by a relay

3. Why are opto isolators normally used between the microcontrollers and the ULN2803?

a) to optimize the current

b) to reduce the back emf

c) to increase the current

d) to increase the voltage

Answer: to reduce the back emf

4. Which of the following is a type of an electromagnetic relay?

a) SPST

b) SPDT

c) DPDT

d) All of the mentioned

Answer: All of the mentioned

5. Reed switches show connectivity whenever they are in the presence of an electrical field?

a) true

b) false

c) can’t say

d) depends on the conditions

Answer: false

6. Which of the following is an application of stepper motors?

a) in printers

b) in robots

c) in vehicles

d) all of the mentioned

Answer: all of the mentioned

7. What are normal 4 step sequence of a stepper motor if we start to move in clockwise direction with 0110 value?

a) 1100,1001,0011,0110

b) 0011,1001,1100,0110

c) 1001,1100,0110,0011

d) 0101,1010,0101,1010

Answer: 0011,1001,1100,0110

8. What is the meaning of a step angle?

a) angle which a stepper motor has

b) angle between the two windings of the stator in a stepper motor

c) minimum degree of rotation associated with a single step

d) angle between the stator and the rotor

Answer: minimum degree of rotation associated with a single step

9. For a normal 4 step sequence, what are the number of teeth required to accomplish a 2 degree step angle?

a) 180

b) 90

c) 360

d) 45

Answer: 45

10. Ounch-inch is a unit of a torque.

a) true

b) false

c) can’t say

d) depends on the situation

Answer: true

SPI Protocol

1. Why do we make the connection of the SCLK for communicating serially between two devices?

a) to get a clock output from the device

b) to synchronize the two devices

c) to obtain an analog output

d) all of the mentioned

Answer: to synchronize the two devices

2. What is the function of the CE pin in SPI?

a) it is used for synchronization

b) it is used as a transmitting pin

c) it is used as a receiving pin

d) it is used to initiate and terminate the data transfer

Answer: it is used to initiate and terminate the data transfer

3. Which of the following is correct?

a) MOSI has the same meaning as the SDO

b) SCLK is used to initiate and terminate the data transfer

c) In 3 wire SPI, there is only one pin for transmission and reception

d) In 3 wire SPI, there are three pins MOSI, MISO and SCLK

Answer: In 3 wire SPI, there is only one pin for transmission and reception

4. If CPHA= 0 and CPOL=1, then which of the following is true?

a) read on rising edge, changed on a falling edge

b) read on falling edge, changed on a rising edge

c) write on rising edge, changed on a falling edge

d) write on rising edge, changed on a falling edge

Answer: read on falling edge, changed on a rising edge

5. In SPI write, LSB goes first?

a) true

b) false

c) can’t be said

d) depends on the cases

Answer: false

6. In AVR, which of the following registers are used for SPI?

a) SPSR

b) SPCR

c) SPDR

d) All of the mentioned

Answer: All of the mentioned

7. How do we set the SPI, to operate in the master mode 1?

a) We set the MSTR bit, and make the CPOL= 1 and CPHA=0

b) We set the MSTR bit, and make the CPOL= 0 and CPHA=1

c) We reset the MSTR bit, and make the CPOL= 1 and CPHA=0

d) We reset the MSTR bit, and make the CPOL= 0 and CPHA=1

Answer: We set the MSTR bit, and make the CPOL= 0 and CPHA=1

8. SPI can act as a half duplex transmission?

a) true

b) false

c) depends on the conditions

d) can’t be said

Answer: false

9. Which frequency is not recommended for SPI clock?

a) fosc/4

b) fosc/64

c) fosc/16

d) fosc/2

Answer: fosc/2

10. To select the value of the clock to be fosc/16, what are the appropriate values?

a) SPI2X= 0, SPR1= 0, SPR0=1

b) SPI2X= 0, SPR1= 1, SPR0=0

c) SPI2X= 1, SPR1= 1, SPR0=0

d) SPI2X= 0, SPR1= 1, SPR0=1

Answer: SPI2X= 0, SPR1= 0, SPR0=1

I2C Protocol

1. Which of the following is correct?

a) I2C is a technique by which data is transmitted with the help of only eight pins

b) SDA is used to synchronize data transfer between two chips

c) TWI is another name for I2C

d) All of the mentioned

Answer: TWI is another name for I2C

2. Which of the following is true about the I2C protocols?

a) the data line cannot change when the clock line is high

b) the data line can change when the clock line is high

c) the clock line cannot change when the data line is high

d) the clock line can change when the data line is high

Answer: the data line cannot change when the clock line is high

3. I2C is a connection oriented communication protocol.

a) true

b) false

c) cant be said

d) depends on the conditions

Answer: true

4. The STOP condition is generated by a

a) high to low change in the SDA line when the SCL is low

b) high to low change in the SDA line when the SCL is high

c) low to high change in the SDA line when the SCL is low

d) low to high change in the SDA line when the SCL is high

Answer: low to high change in the SDA line when the SCL is low

5. For receiving the acknowledgment

a) SDA from the transmitter should be high

b) SDA from the transmitter should be low

c) SDA from receiver should be high

d) SDA from receiver should be low

Answer: SDA from receiver should be low

6. What steps are followed to complete the data transfer?

a) START condition, STOP condition

b) Address packet

c) One or more data packet

d) All of the mentioned

Answer: All of the mentioned

7. I2C is ideal for short distances?

a) true

b) false

c) cant be said

d) depends on the conditions

Answer: true

8. Which of the following is a register used for programming AVR’s I2C module?

a) TWBR

b) TWCR

c) TWSR

d) All of the mentioned

Answer: All of the mentioned

9. Which bit is polled to know that whether the TWI is ready or not?

a) TWWC

b) TWINT

c) TWEA

d) All of the mentioned

Answer: TWINT

10. Is status flag important in multi master systems?

a) yes

b) no

c) depends on the conditions

d) cant be said

Answer: yes

LCD Interfacing

1. In AVR, the LCD operates in two main modes, it can be in 8 bit or 4 bit data.

a) true

b) false

c) depends on the situation

d) can’t be said

Answer: true

2. What can be the sequence of commands that may be used for initializing an LCD?

a) 0x06, 0x0e, 0x01

b) 0x0e, 0x01, 0x80

c) 0x38, 0x0e, 0x01

d) all of the mentioned

Answer: 0x38, 0x0e, 0x01

3. When the LCD operates in the 4 bit mode, then what more commands are added to it?

a) 33

b) 32

c) 28

d) all of the mentioned

Answer: all of the mentioned

4. What is the main function of the LPM instruction used in LCD?

a) for initializing the LCD in the read mode

b) for initializing the LCD in the write mode

c) for sending a long string of characters to the LCD

d) all of the mentioned

Answer: for sending a long string of characters to the LCD

5. The RS pin acts as an

a) input pin

b) output pin

c) any of the mentioned depending on the conditions

d) none of the mentioned

Answer: input pin

6. To latch in information at the data pins of the LCD, we send

a) H-L pulse at the E pin

b) L-H pulse at the E pin

c) A constant H pulse at the E pin

d) A constant L pulse at the E pin

Answer: H-L pulse at the E pin

7. What is the function of the 0x06 command?

a) to clear the LCD

b) to blink the cursor

c) to shift the cursor to the right

d) for selecting the matrix

Answer: to shift the cursor to the right

8. What is the address of the second column and the second row of the 2*20 LCD?

a) 0x80

b) 0x81

c) 0xc0

d) 0xc1

Answer: 0xc1

9. Which of the following commands takes more than 100 microseconds to run?

a) shift cursor left

b) shift cursor right

c) set address location of the DDRAM

d) clear screen

Answer: clear screen

10. For selecting the data pins in an LCD, RS pin should be

a) 1

b) 0

c) F

d) 10

Answer: 1

Keyboard Interfacing

1. In reading the columns of a keyboard matrix, when no key is pressed then all the pins show?

a) 0

b) 1

c) F

d) 7

Answer: 1

2. To see if any key is pressed, all rows are grounded.

a) true

b) false

c) can’t be said

d) depends on the conditions

Answer: true

3. Identify the row and the column for the following case when for the row D3-D0= 1110 and for the column D3-D0= 1101

a) first row and second column

b) first row and third column

c) second row and first column

d) second row and second column

Answer: first row and second column

4. What are the actual steps that are followed in identifying any key that is being pressed?

a) wait for the debounce time

b) identify the key that is pressed

c) initially no key should be pressed

d) all of the mentioned

Answer: all of the mentioned

5. To identify that the key is present in which row and the column

a) we ground the bits of the row one by one

b) we ground the bits of the column one by one

c) we connect the bits of the row to the logic level 1 one by one

d) we can connect the columns to the logic level 1 one by one

Answer: we ground the bits of the row one by one

6. The key detection and the key identification are two different procedures?

a) true

b) false

c) depends on the circumstances

d) difficult to tell

Answer: true

7. What is described by the following command?

KCODE0<<1

a) load KCODE0 with 0

b) rotate the contents of the KCODE0 register to the right

c) rotate the contents of the KCODE0 register to the left

d) none of the mentioned

Answer: rotate the contents of the KCODE0 register to the right

8. If the pins of the keyboard are used as an interrupt, then these pins will cause an interrupt of what type?

a) External hardware interrupt

b) Timer interrupt

c) TI/RI interrupt

d) None of the mentioned

Answer: External hardware interrupt

9. What will happen if the two keys of the keyboard are pressed at a time?

a) both the keys will be displayed on the screen

b) the key which is being actually pressed(for more then 20microseconds) will be displayed

c) the key that is pressed first will be displayed

d) none of the mentioned

Answer: the key which is being actually pressed(for more then 20microseconds) will be displayed

10. Why initially all keys are considered open before detecting the key pressed?

a) to make the task easy

b) to remove the errors caused by other pressing keys during detection

c) to remove the flow problems

d) none of the mentioned

Answer: to remove the errors caused by other pressing keys during detection

ADC, DAC Interfacing

1. Which of the following is correct about the word resolution in ADC DAC converters in AVR’s?

a) it is the smallest change that can be described by an ADC

b) it is equal to Vref/2n (where n represents the number of bits)

c) it is 0.076mV or 76uV for n=16 and Vref=5V

d) all of the mentioned

Answer: all of the mentioned

2. In an ADC, we can calculate the output voltage from the formula

a) Step size / Vin

b) Step size * Vin

c) Vin / step size

d) Vref / step size

Answer: Vin / step size

3. ADC0848 is a ____________ bit converter?

a) 16

b) 4

c) 8

d) 48

Answer: 8

4. Which of the following factors can affect the step size calculation?

a) number of bits

b) input current

c) output current

d) all of the mentioned

Answer: number of bits

5. MAX1112 is a _________ type of ADC converter?

a) parallel

b) 12 bit

c) serial

d) all of the mentioned

Answer: serial

6. Why do we connect a capacitor between the Vref and the Gnd pin?

a) to remove the leakage

b) to ensure more current at that place

c) to make more Vref

d) to make Vref stable and also to increase the precision of the ADC

Answer: to make Vref stable and also to increase the precision of the ADC

7. Which of the following are the registers that are used for controlling the ADC conversion in the AVR?

a) ADCSRA

b) ADMUX

c) SPIOR

d) All of the mentioned

Answer: All of the mentioned

8. What is the internal Vref of an Atmega32 series?

a) 5V

b) 3.3V

c) 2.56V

d) all of the mentioned

Answer: 2.56V

9. The output of a DAC0808 is in the form of ____________

a) electrical pulse

b) current

c) voltage

d) all of the mentioned

Answer: current

10. In a DAC the input is ______ and the output is ______

a) analog, digital

b) current, voltage

c) digital, analog

d) analog, current

Answer: digital, analog

Sensor Interfacing

1. Which of the following is correct about the word sensors?

a) that senses something

b) it is a type of a transducer that converts one form of energy to another

c) it can produce output in the form of electrical pulses, current or voltage

d) all of the mentioned

Answer: all of the mentioned

2. Why do we need to apply the concept of signal conditioning to a sensor?

a) in order to convert it into a desirable form of energy

b) for testing

c) for sensing something

d) all of the mentioned

Answer: in order to convert it into a desirable form of energy

3. Which of the following is correct about LM35 based sensors?

a) its output voltage is directly proportional to the Celsius scale

b) its output voltage is directly proportional to the Fahrenheit scale

c) none of the mentioned

d) all of the mentioned

Answer: its output voltage is directly proportional to the Celsius scale

4. What is the difference between the LM34 and the LM35 based sensors?

a) one requires external calibration while other does not

b) one has output voltage proportional to the Celsius scale while others have to the Fahrenheit scale

c) one is fast other is slow

d) all of the mentioned

Answer: one has output voltage proportional to the Celsius scale while others have to the Fahrenheit scale

5. Every transducer must be connected with the signal conditioning circuit?

a) true

b) false

c) can’t say

d) depends on the conditions

Answer: true

6. LM35 provides _______ V for each degree count?

a) 1

b) 0.1

c) 0.001

d) 10

Answer: 0.001

7. Why for the 8 bit analog input we select Vref as the 2.56V?

a) to obtain each degree count as the 2.56V

b) to get 2.56V at the output

c) to obtain each degree count as the 10mV

d) to get 10mV as the output

Answer: to obtain each degree count as the 10mV

8. What is the temperature for LM35 sensor if the analog output is 0011 1001?

a) 3

b) 9

c) 57

d) 41

Answer: 57

9. In an external hardware, there are how many pins available for the LM35 and the LM34 based sensors?

a) 2

b) 3

c) 10

d) 1

Answer: 3

10. Do LM34 and LM35 based sensors have linear output?

a) yes

b) no

c) depends on the conditions

d) can’t say

Answer: yes