This section contains more frequently asked Microprocessors 8085 Fundamental MCQs in the various University Level and Competitive Examinations.
1. Signal voltage ranges for a logic high and for a logic low in RS-232C standard are
- Low = 0 volt to 1.8 volt, high = 2.0 volt to 5 volt
- Low =-15 volt to –3 vol, high = +3 volt to +15 volt
- Low = +3 volt to +15 volt, high = -3 volt to -15 volt
- Low = 2 volt to 5.0 volt, high = 0 volt to 1.8 volt
B. Low =-15 volt to –3 vol, high = +3 volt to +15 volt
2. The PCI bus is the important bus found in all the new Pentium systems because
- It has plug and play characteristics
- It has ability to function with a 64 bit data bus
- Any Microprocessor can be interfaced to it with PCI controller or bridge
- All of the above
D. All of the above
3. Which of the following statement is true?
- The group of machine cycle is called a state.
- A machine cycle consists of one or more instruction cycle.
- An instruction cycle is made up of machine cycles and a machine cycle is made up of number of states.
- None of the above
B. A machine cycle consists of one or more instruction cycle.
4. 8251 is a
- UART
- USART
- Programmable Interrupt controller
- Programmable interval timer/counter
B. USART
5. 8088 microprocessor has
- 16 bit data bus
- 4 byte pre-fetch queue
- 6 byte pre-fetch queue
- 16 bit address bus
D. 16 bit address bus
6. By what factor does the 8284A clock generator divide the crystal oscillator’s output frequency?
- One
- Two
- Three
- Four
C. Three
7. The memory data bus width in Pentium is
- 16 bit
- 32 bit
- 64 bit
- None of these
C. 64 bit
8. When the 82C55 is reset, its I/O ports are all initializes as
- output port using mode 0
- Input port using mode 1
- output port using mode 1
- Input port using mode 0
D. Input port using mode 0
9. Which microprocessor pins are used to request and acknowledge a DMA transfer?
- reset and ready
- ready and wait
- HOLD and HLDA
- None o these
C. HOLD and HLDA
10. Which of the following statement is false?
- RTOS performs tasks in predictable amount of time
- Windows 98 is RTOS
- Interrupts are used to develop RTOS
- Kernel is the one of component of any OS
B. Windows 98 is RTOS