53 + Mcqs in Signals And Switches Page 1 McqOptions

1.	What is the frequency of a clock waveform if the period of that waveform is1.25 s?
A.	8 kHz
B.	0.8 kHz
C.	0.8 MHz
D.	8 MHz
Answer» D. 8 MHz

Discussion

2.	TTL logic chips must have connections to and ground, even if all inputs and outputs are properly used and tied to valid signals.
A.	True
B.	False
Answer» B. False

Discussion

3.	An indication of cutoff in an bipolar transistor is that the:
A.	collector current is maximum
B.	collector-to-emitter voltage equals zero
C.	base-to-emitter voltage equals 0.7 V
D.	collector to emitter appears to be open
Answer» E.

Discussion

4.	Normal operation of an bipolar transistor requires the base to be ________ with respect to the emitter, and ________ with respect to the collector.
A.	positive, negative
B.	positive, positive
C.	negative, positive
D.	negative, negative
Answer» B. positive, positive

Discussion

5.	An electromechanical relay is operated manually.
A.	1
B.
Answer» C.

Discussion

6.	Manual switches and relays have identical ON and OFF resistances.
A.	1
B.
Answer» C.

Discussion

7.	Serial communications cannot be sped up.
A.	1
B.
Answer» C.

Discussion

8.	The frequency of the clock waveform is defined as the reciprocal of the clock period.
A.	1
B.
Answer» B.

Discussion

9.	The ability to manufacture smaller, more dense components has been fulfilled by SMD.
A.	1
B.
C.	1
D.
Answer» B.

Discussion

10.	With surface-mount technology (SMT), the devices should:
A.	utilize transistor outline connections
B.	mount directly
C.	have parallel connecting pins
D.	require holes and pads
Answer» C. have parallel connecting pins

Discussion

11.	Why, in most applications, are transistor switches used in place of relays?
A.	They consume less power.
B.	They are faster.
C.	They are quieter and smaller.
D.	all of the above
Answer» E.

Discussion

12.	A diode placed in parallel across a relay coil serves what function?
A.	to regulate input voltage
B.	to protect the coil from arcing
C.	to ensure most of the current passes through the coil
D.	to reduce arcing across the relay contacts
Answer» C. to ensure most of the current passes through the coil

Discussion

13.	In a graphical representation of voltage versus time, ________ is displayed on the ________ axis and ________ is displayed on the ________ axis.
A.	time, y, voltage, x
B.	voltage, y, time, x
Answer» C.

Discussion

14.	What is the period of a clock waveform that has a frequency of 15.4 kHz?
A.	649 s
B.	6.49 s
C.	64.9 s
D.	0.649 s
Answer» D. 0.649 s

Discussion

15.	The family of logic that is composed of bipolar junction transistors is ____.
A.	TTL
B.	CMOS
C.	DIP
D.	BJT
Answer» B. CMOS

Discussion

16.	Normal operation of an NPN bipolar transistor requires the base to be ________ with respect to the emitter, and ________ with respect to the collector.
A.	positive, negative
B.	positive, positive
C.	negative, positive
D.	negative, negative
Answer» B. positive, positive

Discussion

17.	The SO package is available for the most popular TTL and CMOS digital logic and analog IC devices.
A.	1
B.
Answer» B.

Discussion

18.	What is the advantage of using serial data transmission over parallel data transmission?
A.	It is slower.
B.	Only one pair of wires is required.
C.	More people use it.
D.	It is faster.
Answer» C. More people use it.

Discussion

19.	What is a disadvantage of CMOS in place of TTL?
A.	It switches slower.
B.	It uses less power.
C.	It is smaller.
D.	cost
Answer» B. It uses less power.

Discussion

20.	What can a relay provide between the triggering source and the output that semiconductor switching devices cannot?
A.	total isolation
B.	faster
C.	higher current rating
D.	total isolation and higher current rating
Answer» E.

Discussion

21.	Determine if diodes D1 and D2 in the given figure are forward or reverse biased.
A.	D1 forward and D2 reverse
B.	D2 forward and D1 reverse
C.	D1 and D2 reverse
D.	D1 and D2 forward
Answer» B. D2 forward and D1 reverse

Discussion

22.	The units for the HIGH time for a periodic wave are ________.
A.	seconds
B.	hertz
C.	cycles
D.	%
Answer» B. hertz

Discussion

23.	When an IC has two rows of parallel connecting pins, the device is referred to as a:
A.	QFP
B.	DIP
C.	TSSOP
D.	CMOS
Answer» C. TSSOP

Discussion

24.	If the input voltage on D1 in the given figure is changed to 0 V, what is the output voltage Vout?
A.	‚Äì5 V
B.	0 V
C.	+5 V
D.	+4.3 V
Answer» C. +5 V

Discussion

25.	What is the advantage of using CMOS logic over TTL?
A.	It switches faster.
B.	It uses less power.
C.	It is larger.
D.	cost
Answer» C. It is larger.

Discussion

26.	Is the transistor in the given figure considered ON or OFF?
A.	OFF
B.	ON
C.	Not enough information is provided.
Answer» B. ON

Discussion

27.	The abbreviation NO, when used with respect to electromechanical relays, stands for not operational.
A.	1
B.
Answer» C.

Discussion

28.	What is the output voltage Vout for the given circuit if the input voltage changes to 0 V?
A.	+12 V
B.	+15 V
C.	+3 V
D.	0 V
Answer» B. +15 V

Discussion

29.	The period of a waveform is the percentage of time the signal is HIGH.
A.	1
B.
Answer» C.

Discussion

30.	Determine the output voltage Vout for the circuit in the given figure.
A.	‚Äì0.5 V
B.	0 V
C.	+5 V
D.	+4.3 V
Answer» E.

Discussion

31.	The CMOS uses bipolar transistors instead of MOSFET.
A.	1
B.
Answer» C.

Discussion

32.	Serial communication can be sped up by:
A.	using silver or gold conductors instead of copper
B.	using high-speed clock signals
C.	adjusting the duty cycle of the binary information
D.	using silver or gold conductors instead of copper and high-speed clock signals
Answer» C. adjusting the duty cycle of the binary information

Discussion

33.	Which device(s) have almost ideal ON and OFF resistances?
A.	electromechanical relays
B.	manual switches
C.	semiconductor devices (diodes and transistors)
D.	electromechanical relays and manual switches
Answer» E.

Discussion

34.	A plot of voltage versus time is called a timing diagram.
A.	1
B.
Answer» B.

Discussion

35.	What is the output voltage from the circuit in the given figure?
A.	+15 V
B.	+12 V
C.	+3 V
D.	0 V
Answer» E.

Discussion

36.	To forward bias a diode, a ________ potential is needed on the ________ and a ________ is needed on the ________.
A.	negative, cathode, positive, anode
B.	negative, anode, positive, cathode
Answer» B. negative, anode, positive, cathode

Discussion

37.	What is used to graphically show the time relationship between two or more digital waveforms?
A.	reference diagram
B.	timing diagram
C.	voltage curve
D.	load line
Answer» C. voltage curve

Discussion

38.	Most modern digital systems are based on semiconductor technology.
A.	1
B.
Answer» B.

Discussion

39.	A TTL totem-pole circuit is designed so that the output transistors:
A.	are always on together
B.	provide phase splitting
C.	provide voltage regulation
D.	are never on together
Answer» E.

Discussion

40.	An indication of cutoff in an NPN bipolar transistor is that the:
A.	collector current is maximum
B.	collector-to-emitter voltage equals zero
C.	base-to-emitter voltage equals 0.7 V
D.	collector to emitter appears to be open
Answer» E.

Discussion

41.	Determine the voltage on the collector Vc of the given transistor circuit.
A.	0 V
B.	+10 V
C.	+4.7 V
D.	+0.5 V
Answer» C. +4.7 V

Discussion

42.	How long will it take to serially transmit the hexadecimal number C316 if the clock frequency is 1.5 MHz?
A.	4.69 ms
B.	4.69 s
C.	5.33 ms
D.	5.33 s
Answer» E.

Discussion

43.	The hexadecimal number 4B16 is transmitted as an 8-bit word in parallel. What is the time required for this transmission if the clock frequency is 2.25 MHz?
A.	444 ns
B.	444 s
C.	3.55 s
D.	3.55 ms
Answer» B. 444 s

Discussion

44.	Precise timing is not important in digital signals.
A.	1
B.
C.	1
D.
Answer» C. 1

Discussion

45.	What is the minimum voltage required before a diode will allow current to flow between the cathode and the anode?
A.	0.7 V
B.	0.07 V
C.	4.3 V
D.	0.2 V
Answer» B. 0.07 V

Discussion

46.	What is the frequency of a clock waveform if the period of that waveform is1.25 s?
A.	8 kHz
B.	0.8 kHz
C.	0.8 MHz
D.	8 MHz
Answer» D. 8 MHz

Discussion

47.	Why is parallel data transmission preferred over serial data transmission for most applications?
A.	It is much slower.
B.	It is cheaper.
C.	More people use it.
D.	It is much faster.
Answer» E.

Discussion

48.	Internally, a computer's binary data are almost always transmitted on parallel channels, commonly referred to as the:
A.	parallel bus
B.	serial bus
C.	data bus
D.	memory bus
Answer» D. memory bus

Discussion

49.	If the input voltage on the base of the transistor in the given figure is changed to +10 V, what is the new voltage at the collector Vc?
A.	Not enough information is provided.
B.	Vc = 10 V
C.	Vc = 0 V
D.	Vc = 5 V
Answer» D. Vc = 5 V

Discussion

50.	TTL logic chips must have connections to Vcc and ground, even if all inputs and outputs are properly used and tied to valid signals.
A.	1
B.
C.	+12 V
D.	+15 V
Answer» B.

Discussion

Explore topic-wise MCQs in Digital Electronics.

What is the frequency of a clock waveform if the period of that waveform is1.25 s?

TTL logic chips must have connections to and ground, even if all inputs and outputs are properly used and tied to valid signals.

An indication of cutoff in an bipolar transistor is that the:

Normal operation of an bipolar transistor requires the base to be ________ with respect to the emitter, and ________ with respect to the collector.

An electromechanical relay is operated manually.

Manual switches and relays have identical ON and OFF resistances.

Serial communications cannot be sped up.

The frequency of the clock waveform is defined as the reciprocal of the clock period.

The ability to manufacture smaller, more dense components has been fulfilled by SMD.

With surface-mount technology (SMT), the devices should:

Why, in most applications, are transistor switches used in place of relays?

A diode placed in parallel across a relay coil serves what function?

In a graphical representation of voltage versus time, ________ is displayed on the ________ axis and ________ is displayed on the ________ axis.

What is the period of a clock waveform that has a frequency of 15.4 kHz?

The family of logic that is composed of bipolar junction transistors is ____.

Normal operation of an NPN bipolar transistor requires the base to be ________ with respect to the emitter, and ________ with respect to the collector.

The SO package is available for the most popular TTL and CMOS digital logic and analog IC devices.

What is the advantage of using serial data transmission over parallel data transmission?

What is a disadvantage of CMOS in place of TTL?

What can a relay provide between the triggering source and the output that semiconductor switching devices cannot?

Determine if diodes D1 and D2 in the given figure are forward or reverse biased.

The units for the HIGH time for a periodic wave are ________.

When an IC has two rows of parallel connecting pins, the device is referred to as a:

If the input voltage on D1 in the given figure is changed to 0 V, what is the output voltage Vout?

What is the advantage of using CMOS logic over TTL?

Is the transistor in the given figure considered ON or OFF?

The abbreviation NO, when used with respect to electromechanical relays, stands for not operational.

What is the output voltage Vout for the given circuit if the input voltage changes to 0 V?

The period of a waveform is the percentage of time the signal is HIGH.

Determine the output voltage Vout for the circuit in the given figure.

The CMOS uses bipolar transistors instead of MOSFET.

Serial communication can be sped up by:

Which device(s) have almost ideal ON and OFF resistances?

A plot of voltage versus time is called a timing diagram.

What is the output voltage from the circuit in the given figure?

To forward bias a diode, a ________ potential is needed on the ________ and a ________ is needed on the ________.

What is used to graphically show the time relationship between two or more digital waveforms?

Most modern digital systems are based on semiconductor technology.

A TTL totem-pole circuit is designed so that the output transistors:

An indication of cutoff in an NPN bipolar transistor is that the:

Determine the voltage on the collector Vc of the given transistor circuit.

How long will it take to serially transmit the hexadecimal number C316 if the clock frequency is 1.5 MHz?

The hexadecimal number 4B16 is transmitted as an 8-bit word in parallel. What is the time required for this transmission if the clock frequency is 2.25 MHz?

Precise timing is not important in digital signals.

What is the minimum voltage required before a diode will allow current to flow between the cathode and the anode?

What is the frequency of a clock waveform if the period of that waveform is1.25 s?

Why is parallel data transmission preferred over serial data transmission for most applications?

Internally, a computer's binary data are almost always transmitted on parallel channels, commonly referred to as the:

If the input voltage on the base of the transistor in the given figure is changed to +10 V, what is the new voltage at the collector Vc?

TTL logic chips must have connections to Vcc and ground, even if all inputs and outputs are properly used and tied to valid signals.

Normal operation of an bipolar transistor requires the base to be with respect to the emitter, and with respect to the collector.

In a graphical representation of voltage versus time, is displayed on the axis and is displayed on the axis.

Normal operation of an NPN bipolar transistor requires the base to be with respect to the emitter, and with respect to the collector.

To forward bias a diode, a potential is needed on the and a is needed on the .