Answer:
113.7
Explanation:
maximum distance (s) = 8.9 km
reference intensity (I0) = 1 x 10^{-12} W/m^{2}
power of a juvenile howler monkey (p) = 63 x 10^{-6} W
distance (r) = 210 m
intensity (I) = power/area
where we assume the area of a sphere due to the uniformity of the output in all directions
area = 4π = 4π x
= 554,176.9 m^{2}
intensity (I) =
therefore the desired ratio I/I0 = = 113.7
Answer:
Resistance = 3.35* Ω
Explanation:
Since resistance R = ρ
whereas
resistivity is given for two ends. At the left end resistivity is whereas x at the left end will be 0 as distance is zero. Thus
At the right end x will be equal to the length of the rod, so
Thus resistance will be R = ρ
where A = π
so,
To solve this problem it is necessary to apply the concepts related to the magnetic dipole moment in terms of the current and the surface area, as well as the current density, as a function of the current over the area.
Part A) By definition we know that magnetic dipole moment is
Where,
I = Current
S = Area
Replacing with our values we have that,
Re-arrange to find I,
Part B) To find the Current density we need to find the cross sectional area of the Wire:
Finally the current density is simply J
PART C) Finally to make the comparison with the given values we have to cross-sectional area would be
Therefore the current density would be
Comparing the two values we can see that the 2mm wire has a higher current density.