Which type of memory needs to be regularly refreshed?

Question

Question

This question was previously asked in

RRB ALP Mechanic Radio & TV 23 Jan 2019 Official Paper (Shift 3)

Answer 1

The correct option is 1

Concept:

DRAM:

In a DRAM, a capacitor to store a bit of data is used along with a MOSFET (transfer device) which acts as a switch.
It requires only one transistor to store one-bit data whereas SRAM requires 6 transistors.
The information is stored in a capacitor.
Both read and write operations cannot be performed simultaneously.
To store one bit of data, DRAM needs one transistor and one capacitor.
Since the capacitor stores the data in the form of charge.
To keep the charge stored for a long duration, the capacitor needs to constantly be refreshed. So DRAM is slower and used for main memory.