Why capacitor pass A.C and Block D.C ?

Question Posted / pawan kumar

4 Answers
9826 Views
Honeywell, JIET, LG, I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

Why capacitor pass A.C and Block D.C ?..

Answer / premalatha

The way capacitors and resistors behave is totally
different. While resistors allow a current to flow through
them which is proportional to the voltage drop across the
resistor, capacitors oppose a change in voltage across them
by either drawing in or supplying current as they charge or
discharge resp. The flow of current through a capacitor is
thus directly proportional to the rate of change of voltage
across it.

This is given by the relation, i = C* (de/dt) where de/dt is
the instantaneous change in voltage.

As the voltage does not change in the case of DC, de/dt = 0
and the current that is allowed to pass through by the
capacitor is 0. For AC voltage the voltage changes in a
regular manner. Hence here de/dt is not 0 and a current is
allowed to flow through by the capacitor.

Is This Answer Correct ?

49 Yes

4 No

Why capacitor pass A.C and Block D.C ?..

Answer / sirish

Also the Capacitive Reactance Xc = 1/(2*pi*f*C)

and as a DC voltage has no frequency associated with it

f = 0

thereby Xc = infinity, and thus is an open to DC.

In a similar fashion for high frequency circuits like RF,
Caps act as a short as Xc tends towards 0.

Is This Answer Correct ?

28 Yes

0 No

Why capacitor pass A.C and Block D.C ?..

Answer / jagadheesh

capacitor support alternating voltages only but not constant voltages because capacitance is inversely proportional to the frequency and constant voltages are having zero frequency that means capacitance goes infinity so it does not support constant voltages

Is This Answer Correct ?

4 Yes

2 No

Why capacitor pass A.C and Block D.C ?..

Answer / siva krizz

xc=1/c*2*3.14*f
for dc frequencyf=0
therefore xc=infinity and no current flows through it
but for ac there is a particular frequency and the capacitive reactance xc is inversely propotional to it.hence capacitor blocks dc and allows ac and is used in amplifiers to filter dc

Is This Answer Correct ?

0 Yes

0 No

Post New Answer

More Electronics Communications Interview Questions

Why doping is done in semiconductors?

0 Answers

How many maximum PWSA cards can be inserted in a Ultra BTS cabinet How many maximum PWSB cards can be inserted in a Ultra BTS cabinet How many maximum PWSC cards can be inserted in a Ultra BTS cabinet What is the output power rating of one PWSA card What is the output power rating of one PWSB card What is the output power rating of one PWSC card What is the function of Receiver Multicoupler (M2xA or M6xA) How many TRX's are supported by one Receiver Multicoupler- M2xA How many TRX's are supported by one Receiver Multicoupler- M6xA What is the function of Remote Tune Combiner (RTxx) unit The FIU19(E) units main LED is red. What is the meaning?

0 Answers NSN,

What do you understand by leds?

0 Answers

i want to held the examination of the bpsc.pl gave the condition &prepare to eam &whose subjet are chose

0 Answers

Draw the equivalent circuit of ujt.

0 Answers

What happens to the series current , load current and zener current when the dc input voltage of a zener regulator increases?

0 Answers

What happens if an amplifier is biased at cutoff or at saturation?

0 Answers

what is angle and amplitude modulation? what is noise in modulation?