Digital Logic and Design MCQs with Answers
Practice important Digital Logic and Design MCQs with answers and explanations.
Chapter: 6
Q241:
In the NAND-NOR universal gates implementation, how is a NAND gate created using NOR gates?
A. By using three NOR gates
B. By using four NOR gates
C. By using two NOR gates
D. By using one NOR gate
Correct Answer:
B
Chapter: 6
Q242:
Which gate outputs 1 when all its inputs are 0?
A. NAND Gate
B. NOR Gate
C. AND Gate
D. XOR Gate
Correct Answer:
B
Chapter: 6
Q243:
What does the XOR gate output when its inputs are both 1?
A. 1
B. zero
C. Undefined
D. High impedance
Correct Answer:
B
Chapter: 6
Q244:
What is the output of an XNOR gate when both inputs are the same?
A. zero
B. 1
C. High impedance
D. Undefined
Correct Answer:
B
Chapter: 6
Q245:
Which technology is characterized by high switching speed and high power consumption?
A. CMOS
B. TTL
C. ECL
D. PMOS
Correct Answer:
B
Chapter: 6
Q246:
What does the output of a 3-input NAND gate become when one input is 0?
A. zero
B. 1
C. Undefined
D. High impedance
Correct Answer:
A
Chapter: 6
Q247:
How many inputs does the 74XX86 IC have?
A. Two
B. Four
C. Six
D. Eight
Correct Answer:
A
Chapter: 6
Q248:
What is the main advantage of CMOS technology compared to TTL?
A. Higher power consumption
B. Slower switching speed
C. Higher chip density
D. Lower chip density
Correct Answer:
C
Chapter: 6
Q249:
What is the function of a NOT gate in digital logic circuits?
A. Inverts the input signal
B. Performs logical AND
C. Performs logical OR
D. Performs logical XOR
Correct Answer:
A
Chapter: 6
Q250:
In a washing machine controller using NOR gates, what does the NOR gate output indicate?
A. Washing machine is functioning normally
B. Washing machine needs maintenance
C. Washing machine is overloaded
D. Washing machine lid is open
Correct Answer:
A
Chapter: 6
Q251:
How does the output of an XOR gate change when an additional input is added to a 2-input XOR gate?
A. It remains the same
B. It becomes a 3-input XOR gate
C. It becomes a XNOR gate
D. It turns into a NOR gate
Correct Answer:
B
Chapter: 6
Q252:
How is a NOT gate implemented using TTL technology?
A. Using a BJT
B. Using a MOSFET
C. Using a combination of MOSFETs
D. Using a combination of BJTs
Correct Answer:
A
Chapter: 7
Q253:
What is the typical supply voltage for TTL-based devices?
A. +3.3V
B. +5V
C. +12V
D. +15V
Correct Answer:
B
Chapter: 7
Q254:
Which TTL series has the fastest switching speed and lowest power consumption?
A. 74 Standard TTL
B. 74LS Low-Power Schottky TTL
C. 74F Fast TTL
D. 74ALS Advanced Low-Power Schottky TTL
Correct Answer:
D
Chapter: 7
Q255:
What is the input voltage range for a logic high signal in TTL?
A. 0 to 0.8V
B. 2 to 5V
C. 0 to 2V
D. 2.4 to 5V
Correct Answer:
B
Chapter: 7
Q256:
What is the minimum acceptable input voltage for a logic high signal in CMOS 5V series?
A. 3.0V
B. 3.5V
C. 4.0V
D. 4.4V
Correct Answer:
B
Chapter: 7
Q257:
What is the output voltage range for a logic low signal in TTL?
A. 0 to 0.4V
B. 0 to 0.8V
C. 0.4 to 0.8V
D. 2.4 to 5V
Correct Answer:
A
Chapter: 7
Q258:
What is the noise margin high (VNH) for CMOS 5 volt series?
A. 0.4V
B. 0.9V
C. 1.17V
D. 2.0V
Correct Answer:
B
Chapter: 7
Q259:
What is the power dissipation of a TTL gate when operating at logic high state?
A. 1.5 mA
B. 2.0 mA
C. 3.0 mA
D. 4.0 mA
Correct Answer:
A
Chapter: 7
Q260:
How does the power dissipation in CMOS devices change with frequency?
A. It decreases
B. It remains constant
C. It increases
D. It decreases initially then increases
Correct Answer:
C