Answer:
200A
Explanation:
Given that
the distance between earth surface and power cable d = 8m
when the current is flowing through cable , the magnitude flux density at the surface is 15μT
when the current flow throught is zero the magnitude flux density at the surface is 20μT
The change in flux density due to the current flowing in the power cable is
B = 20μT - 15μT
B =5μT -----(1)
The expression of magnitude flux density produced by the current carrying cable is
-----(2)
Substitute the value of flux density
B from eqn 1 and eqn 2
Therefore, the magnitude of current I is 200A
Answer:
d) Wind
Explanation:
Secondary energy is energy produced by converting energy available in its natural state in the environment. Hence Wind is a primary source not a secondary source
Answer:
a) the one with a lower orbit b) the one with a higher orbit
Explanation:
Let's consider orbital mechanics. To get an object in orbit, we need it to fall to earth parallel to the earth's surface. To understand it easily imagine a projectile thrown horizontally further and further away, at one point, the projectile hits the cannon from behind. Considering there is no wind resistance, that would be a projecile in orbit.
In other words, the circular orbits of some objects around a massive body are due to the equality between centrifugal acceleration and gravity acceleration.
.
so the velocity is
where "G" is the gravitational constant, "M" the mass of the massive body and "r" the distance between the object and the center of gravity of mass M. As you can note, if "r" increase, "v" decrease.
The orbital period of any object in orbit is
where "a" is length of semi-major axis (a = r in circular orbits). So if "r" increase, "T" increase.
The answer is A. Human Society.
