Answer:
Option A
The cost of keeping the semiconductor below the critical temperature is unreasonable
Explanation:
First of all, we need to understand what superconductors are. Superconductors are special materials that conduct electrical current with almost zero resistance. This means that there is little or no need for a voltage source to be connected to them. As a matter of fact, once a superconductor is connected to a power supply, one can remove the power supply and the current will still flow.
However, most superconducts can only conduct at very low temperatures up to -200 degrees Celcius. This is because, at that temperature, their atoms and molecules are relatively settled, hence they pose little or no resistance to the flow of current.
This as you can guess is extremely difficult to do, as you will need a lot of effort to cool it to that temperature and maintain it.
This makes option a the answer:
The cost of keeping the semiconductor below the critical temperature is unreasonable.
Ocean currents can be generated by wind, density differences in watermasses caused by temperature and salinity variations, gravity, and events such as earthquakes
Answer:
The value is 
Explanation:
From the question we are told that
The operating temperature is 
The emissivity is 
The power rating is 
Generally the area is mathematically represented as
Where 
is the Stefan Boltzmann constant with value
So
Resultant force= (2*6^2)^(1/2)
=8.5m/s
answer is B.
Answer:C
Explanation:BECASE THEY ARE ONE OF THE PEST KILLERS SRY BUT IM THE MYSTER MAN WHOOOSH ????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? OH AND PLS FOR BRAINIEST
