Power: An ac signal is applied across a 40-mH inductor and a 100-? resistor. If the power factor of this circuit is 0.40, what is the frequency of the ac signal?
A. 160 Hz
B. 200 Hz
C. 410 Hz
D. 600 Hz
E. 910 Hz
Answer: E
You might also like to view...
Why was it thought that Titan may have oceans of methane?
A) Titan's atmosphere contains traces of methane. Similarly, Earth's atmosphere contains traces of water vapor. So, scientist thought Titan should have methane oceans. B) The atmospheric pressure at Titan's surface and its surface temperature are such that methane should be liquid on Titan's surface. C) The abundance of hydrocarbons in the atmosphere of Titan, led scientists to believe that Titan had an abundance of methane on its surface. D) Titan's atmosphere is like Earth's (mostly nitrogen), but its temperature is too low for water to be in the liquid phase. The only other possible liquid was methane. E) Since Saturn has methane ice in its atmosphere, methane should be abundant in this region of the solar system. The sheer abundance of methane in the region led scientists to hypothesize methane oceans on Titan.
A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. The ball to reach the ground first is the
A) regular ball. B) lead-filled ball. C) same for both
If the source moves away from you, and at the same time you run away from the source, the frequency you hear is the same as f
Indicate whether the statement is true or false
The strength of gravity within a molecular cloud depends on
A) density only. B) temperature only. C) density and temperature. D) composition. E) thermal pressure.