Questions

Water has the maximum density at 4oC. So at this temperature, it sinks down to bottom and stays here. If it cools further, it will become less dense and move up. So while the upper layers can cool enough to form ice, the bottom layers remain as water at  4oC .  

Therefore, (C) is correct.

Australia is the smallest of all the continents

The MESI protocol is also known as illinois protocol due to its development the University of illinois at Urbana-Champaign and MESI is a widely used cache coherency and memory coherence protocol.

MESI is the most common which supports write-back cache. its use in personal computers became widespread with the introduction of intel's pentium processor to "support the more efficient write-back cache in addition to the write-through cache previously used by the Intel 486 processor"/

Here the given Number Puzzle follows a pattern that, Sum of the numbers on the corners on the two squares is same and is equal to 54.

i.e,

13 + 15 + 14 + 12 = 54 

and

8 + 22 + 9 + 15 = 54

Wireless transmission can be done via any of the Infrared waves, Radio waves or Microwaves.

Here the puzzle follows the logic that

Right side number = sum of the number on the left side and the previous number on the left side

=> 6 = 4+2

=> 10 = 6+4

=> ? = 16+10 = 26.