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
The lord of the greeks answer d
A trough is the lowest point in a wave.
C. 2000 calories.
Explanation/calculation:
Specific heat capacity = calories / mass * (final temperature - initial temperature)
1 = calories / 100 * (60 - 40)
1 = calories / 100 * 20
1 * (100 * 20) = calories
1 * 2000 = calories
2000 = calories
Scattering occurs when light changes direction after colliding with particles of matter.