Which of the following memories must be refreshed many times per second?

The correct answer is Dynamic because Dynamic Random Access Memory (DRAM) relies on capacitors that naturally leak electrical charge and must be continuously refilled to retain data.

• Step 1 (Technical Concept): Inside a DRAM chip, each bit of data is stored in a tiny configuration of a single transistor and a single capacitor. Because capacitors naturally lose their stored electrons over time, the memory controller must read and rewrite every single cell thousands of times per second to prevent data corruption.


• Step 2 (Trade-off): While this refreshing cycle makes dynamic memory slightly slower than static memory, its simple design allows for much higher storage densities and significantly lower manufacturing costs, making it the standard choice for main system RAM.


• Incorrect Options:
  
  
  
  • Static RAM is incorrect because SRAM uses flip-flops to store data bits, holding its state continuously without needing refresh cycles as long as power is maintained.
  
  
  • EPROM is incorrect because Erasable Programmable Read-Only Memory is a non-volatile medium that permanently retains its contents until it is wiped using strong ultraviolet light.
  
  
  • ROM is incorrect because standard Read-Only Memory is hardwired during manufacturing to store permanent startup instructions and does not require active power or refreshing.