Imp Questions of OS for Interviews
1. RAM vs ROM: What's the Difference?
The full form of RAM is Random Access Memory. The information stored in this type of memory is lost when the power supply to the PC or laptop is switched off. The information stored in RAM can be checked with the help of BIOS. It is generally known as the main memory, or temporary memory or cache memory or volatile memory of the computer system.
Types of RAM
DRAM - Dynamic RAM must be continuously refreshed, or otherwise, all contents are lost.
SRAM - Static RAM is faster, needs less power but is more expensive. However, it does need to be refreshed like DRAM.
Synchronous Dynamic RAM (SDRAM) - This type of RAM can run at very high clock speeds.
DDR - Double Data Rate provides synchronous Random Access Memory
The full form of ROM is a Read-Only Memory. It is a permanent type of memory. Its content are not lost when the power supply is switched off. The computer manufacturer decides the information of ROM, and it is permanently stored at the time of manufacturing, which cannot be overwritten by the user.
Characteristics of ROM
You can write data only once. However, once it is written, you can read it any number of times
A ROM chip is used mainly in the start-up process of a modern computer
Types of ROM
EPROM: The full form of EPROM is Erasable Programmable Read-only memory. It stores instructions, but you can erase only by exposing the memory to ultraviolet light.
PROM: The full form of PROM is Programmable Read-Only memory. This type of ROM is written or programmed using a particular device.
EEPROM stands for electrically Erasable Programmable Read-Only Memory. It stores and deletes instructions on a special circuit.
Mask ROM is a full form of MROM is a type of read-only memory (ROM) whose contents can be programmed only by an integrated circuit manufacturer.
2. Difference Between SRAM and DRAM
SRAM | DRAM |
SRAM has lower access time, which is faster compared to DRAM. | DRAM has a higher access time. It is slower than SRAM. |
SRAM is costlier than DRAM. | DRAM cost is lesser compared to SRAM. |
SRAM needs a constant power supply, which means it consumes more power. | DRAM requires reduced power consumption as the information stored in the capacitor. |
Uses transistors and latches. | Uses capacitors and very few transistors. |
L2 and L3 CPU cache units are some general application of an SRAM. | The DRAM is mostly found as the main memory in computers. |
The storage capacity of SRAM is 1MB to 16MB. | The storage capacity of DRAM is 1 GB to 16GB. |
SRAM is in the form of on-chip memory. | DRAM has the characteristics of off-chip memory. |
The SRAM is widely used on the processor or lodged between the main memory and processor of your computer. | The DRAM is placed on the motherboard. |
SRAM is of a smaller size. | DRAM is available in larger storage capacity. |
This type of RAM works on the principle of changing the direction of current through switches. | This type of RAM works on holding the charges. |
3.What is the Difference Between PROM, EPROM, and EEPROM
What is PROM
The PROM chip was commonly used in earlier computers’ BIOS systems. we cannot reprogram it. Instead, we have to discard that and replace it with a new chip.
What is EPROM
EPROM stands for Erasable Programmable Read Only Memory. We can erase and reprogram an EPROM without replacing it. It is possible to erase and write to it by exposing the memory chip to ultraviolet light. EPROM is used more commonly than PROM because it allows the manufacturers to modify or reprogram the chip.
What is EEPROM
EEPROM stands for Electrically Erasable Programmable Read-Only Memory. It is a memory chip that we can erase and reprogram using electrical charge. It consists of a collection of floating gate transistors. The flash memory is a type of EEPROM which has a higher density and lower number of write cycles. EEPROM is a replacement of both PROM and EPROM. It is used in many applications including computers, microcontrollers, smart cards, etc. to store data, erase and to reprogram.
4. Difference between virtualization and containerization
Virtualization is the technology which can simulate your physical hardware (such as CPU cores, memory, disk) and represent it as seperate machine. It has its own Guest OS, Kernel, process, drivers and etc. Therefore, it is hardware level virtualization. Most common technology is VMware and VirtualBox
Containerization is os-level virtualization. It doesn't simulate the entire physical machine. It just simulate the OS of your machine. Therefore multiple applications can share the same OS kernel. Container play similar roles to virtual machine but without hardware virtualization. Most common container technology is Docker
5. What Is UEFI, and How Is It Different from BIOS?
6. What’s the Difference Between GPT and MBR When Partitioning a Drive?
7. What is a socket, kernel and monolithic kernel ?
Kernel is the core part of an operating system. it manages the system resources. Kernel is like a bridge between application and hardware of the computer. The Kernel can be classified further into two categories, Microkernel and Monolithic Kernel.
Microkernel is the one in which user services and kernel services are kept in separate address space.
Monolithic kernel user services and kernel services both are kept in the same address space.
Key Differences Between Microkernel and Monolithic Kernel
The basic point on which microkernel and monolithic kernel is distinguished is that microkernel implement user services and kernel services in different address spaces and monolithic kernel implement both user services and kernel services under same address space.
The size of microkernel is small as only kernel services reside in the kernel address space. However, the size of monolithic kernel is comparatively larger than microkernel because both kernel services and user services reside in the same address space.
The execution of monolithic kernel is faster as the communication between application and hardware is established using the system call. On the other hands, the execution of microkernel is slow as the communication between application and hardware of the system is established through message passing.
Microkernel is more secure than monolithic kernel as if a service fails in microkernel the operating system remain unaffected. On the other hands, if a service fails in monolithic kernel entire system fails.
Read this Questions:
https://www.geeksforgeeks.org/commonly-asked-operating-systems-interview-questions/
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