Explore topic-wise MCQs in Engineering.

The number of input combinations for a 4-input gate is ________.

When does the output of a NOR gate = 0?

Interfacing (74HCMOS to 74ALSTTl or 74TTL to 74LSTTL) can be done with no danger.

When does the output of a NAND gate = 1?

The basic part numbers of ICs are the same regardless of the manufacturer because digital logic ICs have been standardized.

Schottky logic overcomes the saturation and stored charge problem by placing a Schottky diode across the base-to-collector junction.

PLDs did not gain widespread acceptance with digital until the mid-1980s, when a device called a PAL was introduced.

Expanders make it possible to increase the number of terms in a programmable SOP operation.

Exclusive-AND gates are needed for conversions between Gray code and binary code.

Different instruction sets must make up for the various members of the 8051 family.

The ADC 0804 is an analog-to-digital converter that provides 8-bit output resolution that can be directly interfaced to a microcontroller.

Writing counter/loop programs is much more difficult with the introduction of the DJNA and the CJNE instructions.

The 8051 is a 40-pin IC. Twenty-two pins are needed for the four I/O ports.

Up to 65K of code memory and 65K of data memory can be added to any of the 8051 family members.

An effective time delay device can be constructed by using the propagation delay characteristic of parallel shift registers.

The term synchronous refers to events that do not occur at the same time.

When a J-K flip-flop is used in a circuit, we only have to consider the level at J and K at the active clock edge to know the states of the outputs.

Most sequential circuits contain a combinational logic section and a memory section.

Phototransistors have varying resistance from collector to emitter, depending on how much light strikes them.

A serial in/serial out shift register transfers data from one line of a parallel bus to another line one bit at a time.

The serial in/parallel out shift register transfers data from one parallel data bus to another parallel data bus one bit at a time across a single line.

The 74154 is a 1-of-16 decoder. It accepts a 4-bit binary input.

The current across the MSB "rung" of a 4-bit R/2R ladder DAC if the reference voltage is 5 v and R is 8 is 625 A.

In a counter-ramp A/D converter, the end-of-conversion line must be tied back to the clear input of the counter to change the circuit to perform continuous conversions.

A CD player probably uses a sigma/delta D/A converter.

When the inputs of a four-bit D/A converter are connected to a binary up-counter, the output looks like an upward sloping line.

One form of a sigma/delta modulator circuit is designed to convert a continuous analog signal into a modulated bit stream (A/D).

In a binary-weighted D/A converter the sum of all the currents from the binary weighted resistors flows through the operational amplifier.

An eight-bit D/A converter has a resolution of 0.125.

A typical fan-out for most TTL is 9.

A major advantage of ECL logic over TTL and CMOS is ________.

The output of an XOR gate is HIGH only when ________.

A decimal number is converted to BCD by replacing each decimal digit with the appropriate 3-bit binary code.

In ASCII code, the hexadecimal sequence 53 54 55 44 45 4E 54 decodes to STUDENT.

The gates in this figure are implemented using TTL logic. If the input of the inverter is open, and you apply logic pulses to point B, the output of the AND gate will be ________.

The gates in this figure are implemented using TTL logic. If the output of the inverter is open, and you apply logic pulses to point B, the output of the AND gate will be ________.

If A is LOW or B is LOW or BOTH are LOW, then X is LOW. If A is HIGH and B is HIGH, then X is HIGH. These rules specify the operation of a(n) ________.

Analog output current must be converted into a usable voltage. To perform this current-to-voltage conversion a 700 op amp may be used.

A Celsius thermometer is an application for the 8051 microcontroller.

In an 8051 program DA A adjusts the value in the accumulator resulting from an addition into two BCDs.

The DAC0808 and the MC1408 are very popular and inexpensive 8-bit D/A converters.

The delay between a change on the digital input of a DAC and the appearance of the change on the output is called settling time.

The main advantage of the SAR ADC method is its high speed.

One way to determine the resolution of a DAC is to calculate the ratio of one step voltage to the maximum output voltage.

The output voltage or current of a digital-to-analog converter is truly an analog signal.

When the outputs of several open-collector TTL gates are connected together, the gate outputs ________.

Propagation delay is important because ________.

________ output levels would not be a valid LOW for a TTL gate.

Machine language is independent of the type of microprocessor in a computer system.

The PCI bus is a good example of an external bus for personal computers.