Question

Dynamic RAM (DRAM) stores each bit of data in a separate capacitor. Due to leakage, the stored charge tends to dissipate over time and needs to be refreshed periodically. Consider the following statements: \[\begin{array}{rl} \bullet & \text{P: DRAM requires refreshing because it uses capacitors to store bits.} \\ \bullet & \text{Q: SRAM does not require refreshing because it uses flip-flops instead of capacitors.} \\ \bullet & \text{R: DRAM is faster than SRAM because it needs less frequent access.} \\ \bullet & \text{S: DRAM is more suitable for main memory than SRAM due to its density.} \\ \end{array}\]

• A. All statements P, Q, R, and S are true
• B. P, Q, and S are true; R is false.
• C. Only P and Q are true; R is false, and S is irrelevant.
• D. P and S are true; Q and R are false.

Hint:

Remember that DRAM needs refreshing due to its use of capacitors, while SRAM uses flip-flops, which are faster but less dense.

Answer 1

The Correct Option is B

Let's examine each statement:
- Statement P: DRAM requires refreshing because it uses capacitors to store bits, which is true because capacitors leak charge and need to be refreshed periodically.
- Statement Q: SRAM does not require refreshing because it uses flip-flops instead of capacitors, which is true as flip-flops retain their state until power is turned off.
- Statement R: DRAM is faster than SRAM because it needs less frequent access. This is false. SRAM is faster than DRAM because it does not require refreshing and can be accessed more quickly.
- Statement S: DRAM is more suitable for main memory than SRAM due to its density, which is true because DRAM is denser and cheaper than SRAM.
Thus, the correct answer is option (b).