Microprocessors and Microcontrollers (3160914) MCQs

MCQs of Applications and design of microcontroller based systems

Showing 31 to 30 out of 40 Questions
1 2 3 4
31.

What are optoisolators?

(a)

it is a driver
(b)

it is a thing isolated from the entire world
(c)

it is a device that can be used as an electromagnetic relay without a driver
(d)

none of the mentioned
Answer:

Option (c)

32.

How can we control the speed of a stepper motor?

(a)

by controlling its switching rate
(b)

by controlling its torque
(c)

by controlling its wave drive 4 step sequence
(d)

cant be controlled
Answer:

Option (a)

33.

Which of the following can be a unit for torque?

(a)

kg/m2
(b)

ounce-inch
(c)

kg-m3
(d)

g/m
Answer:

Option (b)

34.

How can we change the speed of a DC motor using PWM?

(a)

By changing amplitude of PWM
(b)

By keeping fixed duty cycle
(c)

By changing duty cycle of PWM
(d)

By increasing power of PWM
Answer:

Option (c)

35.

How can the direction of the DC motor be changed?

(a)

by changing the torque
(b)

by changing the switching speed
(c)

by changing the polarity of voltages connected to the leads
(d)

by changing the RPM rating
Answer:

Option (c)

36.

 The 8255 is a ______ chip.

(a)

 Input/Output
(b)

 Analog to Digital
(c)

 Digital to analog
(d)

 None of the mentioned
Answer:

Option (a)

37.

 Which pins of a microcontroller are directly connected with 8255?

(a)

RD
(b)

 WR
(c)

 D0-D7
(d)

 All of the mentioned
Answer:

Option (d)

38.

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

(a)

 CS
(b)

 A1
(c)

 A0
(d)

all of the mentioned
Answer:

Option (d)

39.

 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:

Option (a)

40.

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

(a)

8
(b)

16
(c)

24
(d)

36
Answer:

Option (c)

Showing 31 to 30 out of 40 Questions
1 2 3 4