Electronics and Communication Engineering - Digital Electronics
Exercise :: Digital Electronics - Section 19
| 21. |
Assertion (A): Decoder is not a combinational circuit. Reason (R): Every memory element of semi conductor form has a decoder. |
| A. |
Both A and R are correct and R is correct explanation of A | | B. |
Both A and R are correct but R is not correct explanation of A | | C. |
A is true, R is false | | D. |
A is false, R is true |
Answer: Option B
Explanation:
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| 22. |
In 8085 microprocessor, in order to enable RST 5.5, RST 6.5 and RST 7.5 interrupts, which of the following instruction are needed? |
| A. |
EI only | | B. |
SIM only | | C. |
EI and SIM both | | D. |
None |
Answer: Option C
Explanation:
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| 23. |
A retriggerable one shot is one which |
| A. |
can be triggered only once | | B. |
has two quasi stable states | | C. |
can not be retriggered till the complete pulse appears at output | | D. |
can be retriggered while the output is being generated |
Answer: Option D
Explanation:
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| 24. |
A(A + B) = |
Answer: Option C
Explanation:
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| 25. |
For the K map in the given figure, the simplified expression is
 |
| A. |
xl x2 x4 + x2 x4 + x1 x3 | | B. |
x2 x4 + x2 x4 + x1 x3 | | C. |
x1 x2 x4 + xl x2 + x3 x4 + x2x4 | | D. |
x1 x2 + x2 x3 + x3x4 |
Answer: Option B
Explanation:
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