Computer Memory: Master Guide (कंप्यूटर मेमोरी)
Complete theory and 100 Important MCQs for SSC, IBPS, RRB, and Competitive Exams.
Definition: Computer memory is the storage space in the computer where data is to be processed and instructions required for processing are stored.
(कंप्यूटर मेमोरी वह स्टोरेज है जहाँ डेटा और निर्देश स्टोर किए जाते हैं।)
(कंप्यूटर मेमोरी वह स्टोरेज है जहाँ डेटा और निर्देश स्टोर किए जाते हैं।)
1. Memory Units (मेमोरी इकाइयाँ) - Important for Exam
| Unit | Value | Description |
|---|---|---|
| Bit (b) | 0 or 1 | Smallest unit (Binary Digit) |
| Nibble | 4 Bits | Half Byte |
| Byte (B) | 8 Bits | Basic unit of storage |
| KB (Kilobyte) | 1024 Bytes | 210 Bytes |
| MB (Megabyte) | 1024 KB | 220 Bytes |
| GB (Gigabyte) | 1024 MB | 230 Bytes |
| TB (Terabyte) | 1024 GB | 240 Bytes |
2. Classification of Memory
- Primary Memory (Main Memory): Directly accessible by CPU. Volatile. (e.g., RAM, ROM).
- Secondary Memory (Auxiliary): External storage, Non-volatile. (e.g., HDD, SSD, Pendrive).
- Cache Memory: High-speed SRAM between CPU and RAM.
3. RAM vs ROM (Differences)
| RAM (Random Access Memory) | ROM (Read Only Memory) |
|---|---|
| Volatile (Data lost without power) | Non-Volatile (Permanent) |
| Read/Write allowed | Read only (mostly) |
| Types: SRAM (Static), DRAM (Dynamic) | Types: PROM, EPROM, EEPROM |
🔥 Top 100 Computer Memory MCQs
Click options to check answers instantly.
Basic
1. The smallest unit of digital data is?
डिजिटल डेटा की सबसे छोटी इकाई क्या है?
Correct: Bit (Binary Digit - 0 or 1).
RRB NTPC
2. 1 Terabyte (TB) is equal to?
1 टेराबाइट (TB) किसके बराबर है?
Correct: 1024 GB. Hierarchy: KB > MB > GB > TB > PB.
SSC CGL
3. Half a byte is called?
आधा बाइट क्या कहलाता है?
Correct: Nibble (4 bits).
IBPS
4. Which of the following is Volatile Memory?
निम्नलिखित में से कौन अस्थिर (Volatile) मेमोरी है?
Correct: RAM. Data is lost when power is off.
Important
5. What does 'S' stand for in SRAM?
SRAM में 'S' का क्या अर्थ है?
Correct: Static Random Access Memory. It is faster than DRAM and doesn't need refreshing.
6. Which memory needs refreshing thousands of times per second?
किस मेमोरी को प्रति सेकंड हजारों बार रिफ्रेश करने की आवश्यकता होती है?
Correct: DRAM (Dynamic RAM). It uses capacitors that leak charge.
Railway
7. The startup instructions for a computer are stored in?
कंप्यूटर के स्टार्टअप निर्देश किसमें संग्रहीत होते हैं?
Correct: ROM (BIOS/Bootstrap loader).
8. USB Pen Drive is which type of memory?
USB पेन ड्राइव किस प्रकार की मेमोरी है?
Correct: Secondary (Specifically Flash Memory/EEPROM).
SSC CHSL
9. What is the fastest memory in a computer system?
कंप्यूटर सिस्टम में सबसे तेज मेमोरी कौन सी है?
Correct: Registers (Located inside CPU) > Cache > RAM.
10. CD-ROM stands for?
CD-ROM का पूर्ण रूप है?
Correct: Compact Disc Read Only Memory.
Advanced
11. Virtual Memory is actually?
वर्चुअल मेमोरी वास्तव में क्या है?
Correct: Space on Hard Disk used as extended RAM.
12. Which of the following is NOT a magnetic storage?
निम्नलिखित में से कौन चुंबकीय भंडारण (Magnetic Storage) नहीं है?
Correct: DVD is Optical storage (uses laser).
13. The process of erasing a disk is called?
डिस्क को मिटाने (Erase) की प्रक्रिया क्या कहलाती है?
Correct: Formatting prepares the disk with tracks and sectors.
PO Exam
14. Which memory can be erased by UV light?
यूवी प्रकाश (UV Light) द्वारा किस मेमोरी को मिटाया जा सकता है?
Correct: EPROM (Erasable Programmable ROM).
15. Cache memory works on the principle of?
कैश मेमोरी किस सिद्धांत पर काम करती है?
Correct: Locality of Reference.
16. 1 Petabyte (PB) = ?
1 पेटाबाइट (PB) = ?
Correct: 1024 TB.
17. Which is the main memory of a computer?
कंप्यूटर की मुख्य मेमोरी कौन सी है?
Correct: Internal (Primary memory like RAM).
18. Tracks and Sectors are related to?
ट्रैक और सेक्टर किससे संबंधित हैं?
Correct: Hard Disk. Data is stored in concentric circles called Tracks, divided into Sectors.
RRB
19. Blu-ray Disc can store up to?
ब्लू-रे डिस्क में कितना डेटा स्टोर किया जा सकता है?
Correct: 25 GB to 50 GB (Single vs Dual layer).
20. Flash memory is a type of?
फ्लैश मेमोरी किस प्रकार की है?
Correct: EEPROM (Electrically Erasable).
21. Speed of Hard Disk is measured in?
Correct: RPM (Revolutions Per Minute).
22. Which disk is known as 'WORM' (Write Once Read Many)?
Correct: CD-R (Recordable). Once written, it cannot be changed.
23. Swapping is related to?
Correct: Memory Management. Moving processes between RAM and Disk.
24. 1 KB is equal to?
Correct: 1024 Bytes.
25. Access time of Cache is _____ than RAM.
Correct: Faster.
26. DVD capacity (Standard) is approx?
Correct: 4.7 GB.
27. Which is sequential access memory?
Correct: Magnetic Tape (Like a cassette, you must rewind/fast forward).
28. Which is Non-Volatile?
Correct: ROM.
29. Where does the PC store date/time when off?
Correct: CMOS Battery powers a small chip to keep time.
30. SSD stands for?
Correct: Solid State Drive. No moving parts.
31. Most common type of storage device?
Correct: Magnetic (Though SSDs are taking over).
32. The term 'Memory' applies to?
Correct: Storage.
33. To extend RAM, we use?
Correct: Virtual Memory.
34. Bootstrap program is in?
Correct: ROM.
35. Floppy Disk standard capacity?
Correct: 1.44 MB.
36. A group of 8 bits?
Correct: Byte.
37. Primary memory holds?
Correct: Currently used data.
38. Highest unit here?
Correct: Yottabyte.
39. Firmware is stored in?
Correct: ROM.
40. Pen drive is also called?
Correct: USB Flash Drive.
🚀 Rapid Fire PYQ (SSC, Railway, Banking)
41. Broken sectors in a disk are called?
42. Latency time is related to?
43. Which is an Optical Disk?
44. Memory unit 'Word' is usually?
45. Virtual memory depends on?
46. Buffer is?
47. Fastest access time?
48. Main difference between RAM and ROM?
49. L1 Cache is located?
50. L2 Cache is located?
51. How many bits in an IPv4 address?
52. How many bits in an IPv6 address?
53. ASCII code is?
54. Unicode uses?
55. Data is stored in HDD as?
56. Data is stored in CD as?
57. 'Auxiliary Storage' is?
58. What is a 'Hit' in cache?
59. What is a 'Miss' in cache?
60. Seek Time is?
61. SIMM stands for?
62. DIMM stands for?
63. RAM located on Video Card is?
64. Main folder on a storage device?
65. Zip Disk capacity?
66. 1 Zettabyte (ZB) = ?
67. FAT stands for?
68. NTFS stands for?
69. Fragmentation causes?
70. Defragmentation does what?
🎯 Final Challenge: Questions 71-100
71. Which recording format is used in Floppy Disks?
72. 'Nibble' is equal to?
73. The memory which is programmed at the time of manufacturing?
74. A 32-bit word computer can access how many bytes at a time?
75. Which memory is used for storing data that does not change?
76. MBR stands for?
77. What is the main folder on a disk called?
78. How many pins in a standard DDR3 DIMM?
79. Which is faster: L1 Cache or L2 Cache?
80. The time taken to read/write data in memory is called?
81. In a QR Code, what does QR stand for?
82. Which device uses a laser to read/write data?
83. 1 Yottabyte is equal to?
84. Data on a floppy disk is organized in rings called?
85. Another name for Main Memory is?
86. Which file system is used by default in Windows 10?
87. The amount of data a disk can hold is called?
88. Which is an example of sequential access?
89. The concentric circles on a disk are divided into pie slices called?
90. Group of sectors is called?
91. The speed of Supercomputers is measured in?
92. Which memory is non-volatile but can be updated?
93. A half-byte is also known as a?
94. Is 'Cloud Storage' a type of physical memory?
95. RAID stands for?
96. BIOS is stored in?
97. What happens to RAM when computer is turned off?
98. The smallest addressable unit of memory is usually?
99. Which is faster: SSD or HDD?
100. Which type of ROM can be erased by electrical charge?
❓ 50 Computer Memory FAQs
1. What is computer memory?
Computer memory stores data and instructions for processing in a computer system.
2. What are the main types of computer memory?
Primary memory and secondary memory are the two main types.
3. What is primary memory?
Primary memory is directly accessed by CPU and includes RAM, ROM, and cache.
4. What is secondary memory?
Secondary memory is used for permanent storage like HDD and SSD.
5. What is RAM in computer memory?
RAM is volatile memory used for temporary data storage during operation.
6. What does RAM stand for?
RAM stands for Random Access Memory.
7. Is RAM volatile or non-volatile?
RAM is volatile memory.
8. What is ROM?
ROM is non-volatile memory that stores permanent instructions.
9. What does ROM stand for?
ROM stands for Read Only Memory.
10. What is cache memory?
Cache memory is high-speed memory located close to the CPU.
11. Which is the fastest memory?
Cache memory is the fastest type of computer memory.
12. Which memory is permanent?
ROM and secondary memory are permanent storage.
13. What is memory hierarchy?
Memory hierarchy arranges memory types by speed and cost.
14. What is virtual memory?
Virtual memory uses disk space as extended RAM.
15. What is cache used for?
Cache stores frequently used data for faster CPU access.
16. What is SRAM?
SRAM is static RAM used in cache memory.
17. What is DRAM?
DRAM is dynamic RAM used as main memory.
18. Difference between SRAM and DRAM?
SRAM is faster but costly; DRAM is slower but cheaper.
19. What is memory latency?
Memory latency is the delay in accessing stored data.
20. What is memory bandwidth?
It refers to the amount of data transferred per second.
21. What is HDD?
Hard Disk Drive is magnetic secondary storage.
22. What is SSD?
Solid State Drive is faster flash-based storage.
23. Which is faster HDD or SSD?
SSD is much faster than HDD.
24. What is flash memory?
Flash memory is non-volatile storage used in SSDs and pen drives.
25. What is EEPROM?
EEPROM is electrically erasable programmable ROM.
26. What is PROM?
PROM is programmable read-only memory.
27. What is EPROM?
EPROM can be erased using ultraviolet light.
28. What is memory cache level?
Cache levels include L1, L2, and L3.
29. Which cache level is fastest?
L1 cache is the fastest.
30. What is L2 cache?
L2 cache is slower than L1 but larger in size.
31. What is L3 cache?
L3 cache is shared among CPU cores.
32. What is memory address?
It is a unique location identifier in memory.
33. What is memory unit?
Memory is measured in bytes like KB, MB, GB, TB.
34. What is a byte?
A byte equals 8 bits.
35. What is a bit?
A bit is the smallest unit of data (0 or 1).
36. What is memory refresh?
DRAM requires periodic refresh to retain data.
37. What is swapping?
Swapping moves data between RAM and disk.
38. What is memory fragmentation?
It occurs when memory is inefficiently used.
39. What is memory leak?
A memory leak happens when programs fail to release memory.
40. What is buffer memory?
Buffer temporarily holds data during transfer.
41. What is register memory?
Registers are the fastest memory inside CPU.
42. Where are registers located?
Registers are located inside the CPU.
43. What is the slowest memory?
Secondary storage is the slowest.
44. What is memory speed?
Memory speed defines how fast data is accessed.
45. Why is cache expensive?
Because it uses high-speed SRAM technology.
46. What is memory slot?
A slot where RAM modules are installed on motherboard.
47. What is dual-channel memory?
It uses two RAM modules for higher performance.
48. What is memory upgrade?
Increasing RAM or storage capacity.
49. Why is more RAM useful?
More RAM improves multitasking performance.
50. Which memory is best for performance?
Cache and high-speed RAM provide best performance.