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- Question
The output of a standard TTL NAND gate is used to pull an LED indicator LOW. The LED is in series with a 470-Ω resistor. What is the current in the circuit when the LED is on?
Options- A. 7.02 mA
- B. 8.51 mA
- C. 10.63 mA
- D. 5.32 mA
- Correct Answer
- 7.02 mA
- 1. Cascade chains are closely associated with ________.
Options- A. CLBs
- B. SOP functions
- C. logic expansion
- D. all of the above Discuss
- 2. A ________ is user-programmable memory that cannot be erased and reprogrammed.
Options- A. ROM
- B. EPROM
- C. EEPROM
- D. PROM Discuss
- 3. When performing subtraction by addition in the 2's-complement system:
Options- A. the minuend and the subtrahend are both changed to the 2's-complement.
- B. the minuend is changed to 2's-complement and the subtrahend is left in its original form.
- C. the minuend is left in its original form and the subtrahend is changed to its 2's-complement.
- D. the minuend and subtrahend are both left in their original form. Discuss
- 4. The mask ROM is ________.
Options- A. MOS technology
- B. diode technology
- C. resistor-diode technology
- D. DROM technology Discuss
- 5. A logic probe is placed on the output of a gate and the display indicator is dim. A pulser is used on each of the input terminals, but the output indication does not change. What is wrong?
Options- A. The dim indication on the logic probe indicates that the supply voltage is probably low.
- B. The output of the gate appears to be open.
- C. The dim indication is the result of a bad ground connection on the logic probe.
- D. The gate is a tristate device. Discuss
- 6. The range of positive numbers when using an eight-bit two's-complement system is:
Options- A. 0 to 64
- B. 0 to 100
- C. 0 to 127
- D. 0 to 256 Discuss
- 7. With a 200 kHz clock frequency, eight bits can be serially entered into a shift register in ________.
Options- A. 4 ?s
- B. 40 ?s
- C. 400 ?s
- D. 40 ms Discuss
- 8. What is meant by parallel load of a shift register?
Options- A. All FFs are preset with data.
- B. Each FF is loaded with data, one at a time. Discuss
- 9. Why are ROMs called nonvolatile memory?
Options- A. They lose memory when power is removed.
- B. They do not lose memory when power is removed. Discuss
- 10. Dynamic memory cells store a data bit in a ________.
Options- A. diode
- B. resistor
- C. capacitor
- D. flip-flop Discuss
More questions
Correct Answer: all of the above
Correct Answer: PROM
Correct Answer: the minuend is left in its original form and the subtrahend is changed to its 2's-complement.
Correct Answer: MOS technology
Correct Answer: The output of the gate appears to be open.
Correct Answer: 0 to 127
Correct Answer: 40 ?s
Correct Answer: All FFs are preset with data.
Correct Answer: They do not lose memory when power is removed.
Correct Answer: capacitor
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