 ## CuriousTab

Counters (Digital Electronics) Question and Answers-Page first

# Counters problems

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• 1. What is the difference between a 7490 and a 7492?

• Options
• A. 7490 is a MOD-12, 7492 is a MOD-10
• B. 7490 is a MOD-12, 7492 is a MOD-16
• C. 7490 is a MOD-16, 7492 is a MOD-10
• D. 7490 is a MOD-10, 7492 is a MOD-12

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• 2. List the state of each output pin of a 7447 if RBI = 0, LT = 1, A0 = 1, A1 = 0, A2 = 0, and A3 = 1.

• Options
• A. RBO = 0, a = 0, b = 0, c = 0, d = 1, e = 1, f = 0, g = 0
• B. RBO = 1, a = 0, b = 0, c = 0, d = 1, e = 1, f = 0, g = 0
• C. RBO = 0, a = 0, b = 0, c = 0, d = 0, e = 1, f = 0, g = 0
• D. RBO = 1, a = 0, b = 0, c = 0, d = 0, e = 1, f = 0, g = 0

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• 3. The hexadecimal equivalent of 15,536 is ________.

• Options
• A. 3CB0
• B. 3C66
• C. 63C0
• D. 6300

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• 4. Referring to the given figure, at which point is the serial data transferred to the parallel output? • Options
• A. W
• B. X
• C. Y
• D. Z

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• 5. Three cascaded decade counters will divide the input frequency by ________.

• Options
• A. 10
• B. 20
• C. 100
• D. 1,000

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• 6. The terminal count of a 3-bit binary counter in the DOWN mode is ________.

• Options
• A. 000
• B. 111
• C. 101
• D. 010

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• 7. For a one-shot application, how can HDL code be used to make a circuit respond once to each positive transition on its trigger input?

• Options
• A. By using a counter
• B. By using an active clock
• C. By using an immediate reload
• D. By using edge trapping

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• 8. One of the major drawbacks to the use of asynchronous counters is:

• Options
• A. low-frequency applications are limited because of internal propagation delays
• B. high-frequency applications are limited because of internal propagation delays
• C. asynchronous counters do not have major drawbacks and are suitable for use in high- and low-frequency counting applications
• D. asynchronous counters do not have propagation delays and this limits their use in high-frequency applications

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• 9. When two counters are cascaded, the overall MOD number is equal to the ________ of their individual MOD numbers.

• Options
• A. product
• B. sum
• C. log
• D. reciprocal

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• 10. A 4-bit ripple counter consists of flip-flops, which each have a propagation delay from clock to Q output of 15 ns. For the counter to recycle from 1111 to 0000, it takes a total of ________.

• Options
• A. 15 ns
• B. 30 ns
• C. 45 ns
• D. 60 ns

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