Digital Circuits Questions and Answers – Propagation Delay in Ripple Counter

This set of Digital Electronics/Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Propagation Delay in Ripple Counter”.

1. Modulus refers to ____________
a) A method used to fabricate decade counter units
b) The modulus of elasticity, or the ability of a circuit to be stretched from one mode to another
c) An input on a counter that is used to set the counter state, such as UP/DOWN
d) The maximum number of states in a counter sequence
View Answer

Answer: d
Explanation: Modulus is defined as the maximum number of stages/states a counter has. It is independent of the number of states the counter will actually traverse.

2. A sequential circuit design is used to ____________
a) Count up
b) Count down
c) Decode an end count
d) Count in a random order
View Answer

Answer: d
Explanation: A sequential circuit design is used to count in a random manner which is faster than the combinational circuit. It is used for storing data.

3. In general, when using a scope to troubleshoot digital systems, the instrument should be triggered by ____________
a) The A channel or channel 1
b) The vertical input mode, when using more than one channel
c) The system clock
d) Line sync, in order to observe troublesome power line glitches
View Answer

Answer: c
Explanation: All the information is sent from one end to another end through the clock pulse which behaves like a carrier. So, for troubleshooting it should be triggered by the same. Since the system clock is internally produced.
advertisement
advertisement

4. Which counters are often used whenever pulses are to be counted and the results displayed in decimal?
a) Synchronous
b) Bean
c) Decade
d) BCD
View Answer

Answer: d
Explanation: BCD means Binary Coded Decimal, which means that decimal numbers coded of binary numbers. It displays the decimal equivalent of corresponding binary numbers.

5. The ________ counter in the Altera library has controls that allow it to count up or down, and perform synchronous parallel load and asynchronous cascading.
a) 74134
b) LPM
c) Synchronous
d) AHDL
View Answer

Answer: b
Explanation: The library of parameterized modules (LPM) counter in the Altera library has controls that allow it to count up or down, and perform synchronous parallel load and asynchronous cascading.

6. The minimum number of flip-flops that can be used to construct a modulus-5 counter is ____________
a) 3
b) 8
c) 5
d) 10
View Answer

Answer: a
Explanation: The minimum number of flip-flops used in a counter is given by: 2(n-1)<=N<=2n.
Thus, for modulus-5 counter: 22 <= N <= 23, where N = 5 and n = 3.

7. The duty cycle of the most significant bit from a 4-bit (0–9) BCD counter is ____________
a) 20%
b) 50%
c) 10%
d) 80%
View Answer

Answer: a
Explanation: There are 10 states, out of which MSB is high only for (1000, 1001) 2 times. Hence duty cycle is 2/10*100 = 20%. Since the duty cycle is the ratio of on-time to the total time.
advertisement

8. Normally, the synchronous counter is designed using ____________
a) S-R flip-flops
b) J-K flip-flops
c) D flip-flops
d) T flip-flops
View Answer

Answer: b
Explanation: Since J-K flip-flops have options of recovery from toggle condition and by using less number of J-K flip-flops a synchronous counter can be designed. So, it is more preferred. Also, because JK-flip-flops resolves the problem of Forbidden States.

9. MOD-16 counter requires ________ no. of states.
a) 8
b) 4
c) 16
d) 32
View Answer

Answer: c
Explanation: 2n >= N >= 2(n-1), by using this formula we get the value of N=16 for n=4.
advertisement

10. What is a state diagram?
a) It provides the graphical representation of states
b) It provides exactly the same information as the state table
c) It is same as the truth table
d) It is similar to the characteristic equation
View Answer

Answer: b
Explanation: The state diagram provides exactly the same information as the state table and is obtained directly from the state table.

11. High speed counter is ____________
a) Ring counter
b) Ripple counter
c) Synchronous counter
d) Asynchronous counter
View Answer

Answer: c
Explanation: Synchronous counter doesn’t have propagation delay. Propagation delay refers to the amount of time taken in producing the output when the input is altered.

12. Program counter in a digital computer ____________
a) Counts the number of programs run in the machine
b) Counts the number of times a subroutine
c) Counts the number of time the loops are executed
d) Points the memory address of the current or the next instruction
View Answer

Answer: d
Explanation: Program counter in a digital computer points the memory address of the current or the next instruction which is to be executed.

13. Fundamental mode is another name for ____________
a) Level operation
b) Pulse operation
c) Clock operation
d) Edge operation
View Answer

Answer: b
Explanation: Whatever the input given to the devices are in the form of pulses always. That is why it is known as a fundamental mode.

Sanfoundry Global Education & Learning Series – Digital Circuits.

To practice all areas of Digital Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]

advertisement
advertisement
Subscribe to our Newsletters (Subject-wise). Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

Youtube | Telegram | LinkedIn | Instagram | Facebook | Twitter | Pinterest
Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

Subscribe to his free Masterclasses at Youtube & discussions at Telegram SanfoundryClasses.