There are many porperties. You can use Altitude, Temperature, Pressure and Density, but the best one is temperature. The resaon for that is that based on the temperature changes then the athmosphere can be broken into four major layers. Remember that the layers are the following: <span>the </span>troposphere,the<span> </span>stratosphere, <span>the </span>mesosphere<span>, and the</span>thermosphere<span>.</span>
Answer:
Let R1= resistance of 4ohms
R2= resistance of 8ohms
Equivalent resistance R will be
R=R1 + R2
=> 4+8=12ohms
The current through the two resistors will be the same since they are connected in series. Notwithstanding, the voltage will drop to appreciate the change.
Explanation:
When light travels from a medium with higher refractive index into a medium with lower refractive index, there is a maximum angle (called critical angle) for which all the light is reflected, so there is no refraction.
The value of the critical angle is given by:

when n1 is the refractive index of the first medium, while n2 is the refractive index of the second medium. In our case, n1=1.33 (the water) and n1=1.00 (the air). Putting numbers in, we get