Digital Circuits Questions and Answers – Fast Adder & Serial Adder – 2
This set of Digital Electronic/Circuits Quiz focuses on “Fast Adder & Serial Adder – 2”.
1. A serial subtractor can be obtained by converting the serial adder by using the _____________
a) 1’s complement system
b) 2’s complement system
c) 10’s complement
d) 9’s complement
Explanation: A serial subtractor can be obtained by converting the serial adder by using the 2’s complement system. 9’s complement and 10’s complement are used for decimal numbers while adders deal with binary numbers.
2. The hexadecimal number (4B)16 is transmitted as an 8-bit word in parallel. What is the time required for this transmission if the clock frequency is 2.25 MHz?
a) 444 ns
b) 444 s
c) 3.55 s
d) 3.55 ms
Explanation: Because the clock pulse of 4-bit transmits the data of 8-bit word in parallel mode and this transmission is done at 2.25 MHz frequency. We know that: f=1/t and we can find the time required for this transmission by the clock pulse.
Therefore, time = (1/2.25) = 0.4444 us = 444.44 ns ~ 444ns.
3. Internally, a computer’s binary data are always transmitted on parallel channels which is commonly referred to as the __________
a) Parallel bus
b) Serial bus
c) Data bus
d) Memory bus
Explanation: A process consists of 3 types of buses: Control Bus, Data Bus and Address Bus. A computer’s data is always in the binary form which is stored in the bus that transmits the data on any channels. It doesn’t matter that it’s in parallel or serial.
4. What is the frequency of a clock waveform if the period of that waveform is 1.25sec?
a) 8 kHz
b) 0.8 kHz
c) 0.8 MHz
d) 8 MHz
Explanation: By using the formula of frequency, we can find the frequency of clock waveform. Time period(t) of the waveform is = 1.25microseconds
Where ‘t’ is the time taken by the clock waveform;
so, f=0.8 MHz.
5. Why is parallel data transmission preferred over serial data transmission for most applications?
a) It is much slower
b) It is cheaper
c) More people use it
d) It is much faster
Explanation: Parallel data transmission preferred over serial data transmission for most applications because it is much faster as bits are transmitted simultaneously, whereas in serial data transmission, bits are transmitted one by one.
6. With surface-mount technology (SMT), the devices should __________
a) Utilize transistor outline connections
b) Mount directly
c) Have parallel connecting pins
d) Require holes and pads
Explanation: Surface-mount technology (SMT) is a method for producing electronic circuits in which the components are mounted or placed directly onto the surface of printed circuit boards (PCBs). An electronic device so made is called a surface-mount device (SMD). In the industry, it has largely replaced the through-hole technology construction method of fitting components with wire leads into holes in the circuit board. Both technologies can be used on the same board for components not suited to surface mounting such as large transformers and heat-sinked power semiconductors.
7. In most applications, transistor switches used in place of relays?
a) They consume less power
b) They are faster
c) They are quieter and smaller
d) All of the Mentioned
Explanation: Transistors are of less consuming power, faster, quieter, smaller and its implementation is too easy. So, in most applications transistor switches are more preferred. And also, transistors can be current-controlled or voltage-controlled depending on our choice.
8. What can a relay provide between the triggering source and the output that semiconductor switching devices cannot?
a) Total isolation
c) Higher current rating
d) Total isolation and higher current rating
Explanation: A relay provides total isolation and higher current rating between the triggering source and the output that semiconductor switching devices cannot provide. This is why relays are used to drive high watt appliances at offices or other buildings.
9. The serial format for transmitting binary information uses __________
a) A single conductor
b) Multiple conductors
c) Infrared technology
Explanation: A conductor accepts the whole data and arranges it in a serial manner, which is transmitted as binary information. In serial transmission, data is transmitted bit by bit while in parallel transmission data is transmitted simultaneously.
10. Serial communication can be sped up by __________
a) Using silver or gold conductors instead of copper
b) Using high-speed clock signals
c) Adjusting the duty cycle of the binary information
d) Using silver or gold conductors instead of copper and high-speed clock signals
Explanation: For any serial data transmission there is required of continuously data supply and if the input supply (i.e. high speed clock signals) in a high amount the speed of serial communication can be increased. In serial communication, data is transmitted bit by bit. So the use of high speed clock pulses would make the process faster.