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- Question
A 0.3-µF capacitor has an initial charge of 2.7 V. If it is discharged through a 10-kΩ resistor for 6.5 ms, how much voltage will be left across the capacitor?
Options- A. 0.0 V
- B. 0.309 V
- C. 2.7 V
- D. 2.295 V
- Correct Answer
- 0.309 V
- 1. What is another name for a bistable multivibrator?
Options- A. an on-off switch
- B. an oscillator
- C. a flip-flop Discuss
- 2. The pulse width out of a one-shot multivibrator increases when the:
Options- A. supply voltage increases
- B. timing resistor decreases
- C. UTP decreases
- D. timing capacitance increases Discuss
- 3. When a capacitor charges:
Options- A. the voltage across the plates rises exponentially
- B. the circuit current falls exponentially
- C. the capacitor charges to the source voltage in 5×RC seconds
- D. all of the above Discuss
- 4. The output of the astable circuit ________.
Options- A. constantly switches between two states
- B. is LOW until a trigger is received
- C. is HIGH until a trigger is received
- D. floats until triggered Discuss
- 5. With most monostable multivibrators, what is the Q output when no input trigger has occurred?
Options- A. LOW
- B. +5 V
- C. SET
- D. HIGH Discuss
- 6. This program code will be executed once:
STAT: MOV A, #01H JNZ STAT
Options- A. True
- B. False Discuss
- 7. The following program will cause the 8051 to be stuck in a loop:
LOOP: MOV A, #00H JNZ LOOP
Options- A. True
- B. False Discuss
- 8. MOV A, @ R1 will:
Options- A. copy R1 to the accumulator
- B. copy the accumulator to R1
- C. copy the contents of memory whose address is in R1 to the accumulator
- D. copy the accumulator to the contents of memory whose address is in R1 Discuss
- 9. Data transfer from I/O to external data memory can only be done with the MOV command.
Options- A. True
- B. False Discuss
- 10. The total amount of external code memory that can be interfaced to the 8051 is:
Options- A. 32K
- B. 64K
- C. 128K
- D. 256K Discuss
Multivibrators and 555 Timer problems
Search Results
Correct Answer: a flip-flop
Correct Answer: supply voltage increases
Correct Answer: all of the above
Correct Answer: constantly switches between two states
Correct Answer: LOW
Correct Answer: False
Correct Answer: False
Correct Answer: copy the contents of memory whose address is in R1 to the accumulator
Correct Answer: False
Correct Answer: 64K
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