WBJECA 2025 — Computer PYQ

The correct answer is (B) 16 KB.

To find the minimum memory size, we need to understand how the memory chips are organized to match the processor's data bus width.

1. Understand the Data Bus: The computer has a 32-bit wide data bus. This means the CPU fetches 32 bits of data at a time.

2. Understand the Memory Chip: Each chip is specified as $4K\times 8$.

   • $4K$ refers to the number of memory locations (words).

   • $8$ refers to the number of bits per location (data width of the chip).

3. Calculate Chips per Row: To provide a 32-bit wide data path, we must combine several chips in parallel so that their total bit width equals 32 bits.

   $$\text{Number of chips in a row}=\frac{\text{Data Bus Width}}{\text{Chip Width}}=\frac{32\text{ bits}}{8\text{ bits}}=4\text{ chips}$$

4. Calculate Total Memory: Since one row of 4 chips provides a total capacity of $4K$ locations (with each location being 32 bits wide), the smallest memory configuration (one row) is:

   $$\text{Total Memory}=\text{Number of chips}\times \text{Capacity per chip}$$

   $$\text{Total Memory}=4\times (4K\text{ bytes})=16K\text{ bytes}=16\text{ KB}$$

By arranging these four $4K\times 8$ chips in a single bank, the computer achieves a minimum addressable memory size of 16 KB.