a)A capacitor offers infinite resistance to AC and Inductor to DC
b)A capacitor offers infinite resistance to DC and Inductor to AC
c)A capacitor offers no resistance to DC and Inductor to DC
d) A capacitor offers infinite resistance to DC and Inductor offers no resistance to AC
pls send me the correct answer and the reason for the answer ?
2007-02-18 20:41:09 · 4 answers · asked by mura 1 in Science & Mathematics ➔ Engineering
B - A cap is a short to AC and an open to DC. While an inductor is a short to DC and an open to AC.
The reactance of an inductor is 2*pi*f*l. If frequency is large (AC case) the reactance is also large, like and open. If frequency is 0 (DC case), then the reactance is 0, like a short.
For caps, it is just the opposite as reactance = 1 / 2*pi*f*C
2007-02-18 21:21:04 · answer #1 · answered by buckeye_brian31 2 · 0⤊ 0⤋
Answer b) is true.
Intuitively:
Capacitors store potential energy. At DC a finite voltage may apply but no current can flow through the disconnected plates. By Ohm law definition, that is an infinite resistance at DC.
Inductors store kinetic energy which prevents the current from changing. At high frequencies the voltage may change “freely” while the current does not change much. By definition, that is (a large voltage change divided by a zero current change) an infinite resistance at AC.
2007-02-18 21:38:02 · answer #2 · answered by sciquest 4 · 0⤊ 0⤋
we know inductive reactance = 2*pi*f*L
In case of DC(f=0) it will be 0. Hence it will offer no resistance to DC.In case of AC , higher the frequency,the higher will be the resistance.
Now we come to capacitive reactance which is=1/(2*pi*f*C)
in case of DC (f=0),it will be infinite, means it offers infinite resistance to DC.
in case of AC,the higher the frequency ,the lower will be the reactance (resistance).
2007-02-19 01:53:23 · answer #3 · answered by anuj k 1 · 0⤊ 0⤋
B is the correct one...
Since
Capacitance is inversely propotional to frequency.......... So more AC it will allow easily
So only we re providing capacitors for AC grounding in AC to DC Power Supplies.
Inductance is directly propotional to frequency.......... So more DC it will allow easily
2007-02-18 21:27:30 · answer #4 · answered by Long Live Test Cricket 6 · 0⤊ 0⤋