Question

A 26-bit address bus has maximum accessible memory capacity of ______
1. 64 MB
2. 16 MB
3. 1 GB
4. 4 GB

Answer 1

Correct Answer - Option 1 : 64 MB

• The size of the address bus determines how much memory the CPU can address directly. For example, an n-bit address bus can access up to 2ⁿ bytes. 
• A 26-bit address but has a maximum accessible memory capacity of 2²⁶ bytes =  2⁶ ×  2²⁰ bytes = 64 MB. Therefore option 1 is correct

Note:

1 MB =  220 

Assume system as byte-addressable.