Section A — 1 Mark Questions
1. Define primary memory. [1 Mark]
Answer: Primary memory is the computer's main memory that holds data and instructions currently being processed by the CPU.
2. What is the full form of RAM? [1 Mark]
Answer: Random Access Memory.
3. Name the non-volatile type of primary memory. [1 Mark]
Answer: ROM (Read Only Memory).
4. What is the function of cache memory? [1 Mark]
Answer: It serves as a high-speed buffer to store frequently accessed data for faster CPU processing.
5. Is hard disk an example of primary or secondary memory? [1 Mark]
Answer: Secondary memory.
6. Define auxiliary memory. [1 Mark]
Answer: Auxiliary memory refers to secondary storage devices used to store large amounts of data permanently.
7. What is the main characteristic of volatile memory? [1 Mark]
Answer: It loses all stored data when the power supply is turned off.
8. Give an example of an optical disk. [1 Mark]
Answer: CD (Compact Disc) or DVD (Digital Versatile Disc).
9. Which memory is faster: Cache or RAM? [1 Mark]
Answer: Cache memory.
10. Can ROM be modified by the user during normal operation? [1 Mark]
Answer: No, it is generally considered read-only.
11. What does a hard disk use to store data? [1 Mark]
Answer: Magnetic platters.
12. What is the purpose of secondary memory? [1 Mark]
Answer: To provide long-term, non-volatile data storage.
13. Which memory type is closest to the CPU? [1 Mark]
Answer: Cache memory.
14. Is RAM volatile or non-volatile? [1 Mark]
Answer: Volatile.
15. What is the primary role of an optical disk? [1 Mark]
Answer: To store data using laser technology for portable and long-term storage.
16. What does BIOS stand for? [1 Mark]
Answer: Basic Input/Output System.
17. Name one type of optical storage medium. [1 Mark]
Answer: Blu-ray disc.
18. Does secondary memory need power to retain data? [1 Mark]
Answer: No, it is non-volatile.
19. What is a common capacity unit for hard disks? [1 Mark]
Answer: Gigabytes (GB) or Terabytes (TB).
20. Why is cache memory used? [1 Mark]
Answer: To reduce the time taken for the CPU to access data from the slower main RAM.
Section B — 2/3 Mark Questions
1. Differentiate between RAM and ROM. [2 Marks]
Answer: RAM is volatile memory that allows read/write access for temporary data, while ROM is non-volatile memory that retains information even without power and is primarily for reading.
2. Explain the concept of volatile memory with an example. [2 Marks]
Answer: Volatile memory requires power to maintain the stored information. RAM is a classic example; if the computer shuts down, all data in RAM is lost.
3. List two advantages of secondary memory over primary memory. [2 Marks]
Answer: Secondary memory has a much larger storage capacity than primary memory and it is non-volatile, allowing for permanent data retention.
4. What is cache memory and why is it located near the CPU? [3 Marks]
Answer: Cache memory is high-speed storage that holds frequently accessed data. It is located near the CPU to bridge the speed gap between the high-speed processor and the relatively slower main RAM, ensuring faster execution.
5. Briefly describe how optical disks store data. [2 Marks]
Answer: Optical disks store data using digital patterns of pits and lands on the surface, which are read by a laser beam reflecting off the disk surface.
6. Compare Hard Disks and Optical Disks. [3 Marks]
Answer: Hard disks use magnetic technology and offer high capacity with faster access times. Optical disks use laser technology and are generally portable, but offer lower capacity and slower access speeds.
7. Why is auxiliary memory necessary? [2 Marks]
Answer: Auxiliary memory is necessary because primary memory is limited in size and volatile, making it unsuitable for long-term storage of large programs and files.
8. What is the role of ROM during system startup? [3 Marks]
Answer: ROM contains the firmware required to boot the system. When power is turned on, the CPU accesses the ROM to load the BIOS, which identifies hardware components and initializes the operating system.
9. Why do computers use both RAM and Hard Disks? [3 Marks]
Answer: RAM provides high-speed, temporary workspace for active tasks for the CPU, while the Hard Disk provides permanent, massive storage for the OS, applications, and user files that persist even when the computer is off.
10. Explain the difference between primary and auxiliary memory. [2 Marks]
Answer: Primary memory is directly accessible by the CPU for immediate processing (RAM), whereas auxiliary memory is external or secondary storage used for saving data for long periods.
Section C — 5 Mark Questions
1. Explain the hierarchy of computer memory in detail. [5 Marks]
Answer:
Introduction
Memory hierarchy organizes memory based on speed, cost, and capacity. As we move from the top to the bottom, the access speed decreases, the cost per bit decreases, and the storage capacity increases.
Levels of Hierarchy
- Cache Memory: The fastest memory, located closest to the CPU. It holds temporary data that the CPU needs to access frequently.
- Primary Memory (RAM): The main memory directly connected to the CPU. It is volatile and holds active instructions and data.
- Secondary/Auxiliary Memory: These are non-volatile storage devices like hard disks or solid-state drives. They hold large amounts of data that are not immediately required by the CPU but are needed for long-term use.
Conclusion
This structure ensures an optimal balance between the high cost of fast memory and the need for large-capacity, inexpensive storage.
2. Describe the features and working of Hard Disk drives. [5 Marks]
Answer:
Introduction
A Hard Disk Drive (HDD) is the primary secondary storage device in most computers, known for its ability to store large volumes of data permanently.
Working Principle
- Magnetic Storage: Data is stored on circular platters coated with a magnetic material.
- Read/Write Head: An actuator arm moves a magnetic head over the rotating platters to read or write data.
- Rotation and Sectors: The platters spin at high speeds, and the data is organized into concentric circles called tracks and smaller divisions called sectors.
Key Features
- Non-volatile: Retains data without power.
- High Capacity: Can store terabytes of data compared to primary memory.
- Mechanical Nature: Since it has moving parts, it is prone to physical damage if dropped.
3. Compare primary and secondary memory across various parameters. [5 Marks]
Answer:
| Feature | Primary Memory | Secondary Memory |
|---|---|---|
| Access Speed | Very Fast | Relatively Slow |
| Volatility | Volatile | Non-volatile |
| Capacity | Limited (GBs) | High (TBs) |
| Cost per Bit | Expensive | Cheap |
| Usage | Direct CPU access | Long-term storage |
Key Explanations
Primary memory is essential for active task execution but is expensive and limited, which is why secondary memory acts as a necessary supplement to ensure data can be saved reliably and inexpensively over long periods.
4. Discuss the types and roles of ROM (Read Only Memory). [5 Marks]
Answer:
Introduction
ROM is a type of non-volatile primary memory that stores crucial instructions that do not need to be changed during normal computer operation.
Roles
- Bootstrapping: It stores the initial boot program (BIOS/UEFI) that starts the computer when it is powered on.
- Hardware Initialization: It carries out the self-test programs to ensure hardware components are working correctly.
- Firmware Storage: It keeps core instructions for peripherals like keyboards and screens.
Types of ROM
- PROM: Programmable ROM, written once by the user.
- EPROM: Erasable Programmable ROM, which can be erased by UV light and reprogrammed.
- EEPROM: Electrically Erasable Programmable ROM, which can be erased and rewritten electrically.
5. Elaborate on the function of cache memory in modern computer systems. [5 Marks]
Answer:
Introduction
Cache memory is a special high-speed storage mechanism that sits between the CPU and the main memory (RAM) to speed up data retrieval.
How it Works
- Locality of Reference: It operates on the principle that the CPU is likely to use the same data or neighboring data repeatedly.
- Data Fetching: When the CPU needs data, it first checks the cache. If found (a 'Cache Hit'), it accesses it instantly. If not (a 'Cache Miss'), it must fetch it from the slower RAM.
- Multi-level Cache: Computers use L1, L2, and L3 caches. L1 is the smallest and fastest, integrated directly into the CPU core, while L3 is larger and shared across cores.
Advantage
By keeping the most frequently used data closer to the processor, cache memory significantly reduces CPU idle time, leading to much faster overall system performance.