Answer / sujin

For a dc signal frequency is approximately 0.
For a capacitor reactance ( Xc) is 1/2*3.14*f
Since f is or approximately 0 Xc= infinity.
Hence it blocks dc current

Answer / manishsingh

i=C(dV/dt)
for dc instantaneous change in voltage=o
dV/dt=o
...i=o for dc supply mens no current..

so capacitor block dc supply

Answer / bhabani

capacutive reactance is inversely proportional to frequency.
for dc f=0.thus very high reactance to current

Answer / devsingh boda

ANS1,ANS3,ANS4 are correct.ie,
We can answer this question in two ways,
1.Capacitive reactance is inversely proportional to frequency since,Xc=[1/(2*Pi*f*C)] which implies Xc is inversely proportional to f. For dc f=0 , so Xc is approximately equal to infinite(very high).So current does not flow.

2.We know that capacitive current, Ic=C*[dVc/dt]...
If dc supply is applied across capacitor then dVc/dt becomes zero since dc voltage is a constant(steady) voltage.So Ic also becomes zero.

Answer / shahbaz

because the capacitor is used to store the charges and in
const supply there is no any storege is carried out hence
ckt is not complete.

how to find out speed of single phase motor

6 Answers   BARC,

In CTs tan delta point should be earthed , what is the reason behind it?

0 Answers  

What is the min and max ohmic value for earthing?

15 Answers   NewTek, Wipro,

What should be value of Circuit breaker operating time and tripping time?

5 Answers  

What happen when increese more than 50HZ fequincy.

5 Answers  

What is bus-bar?

1 Answers  

why is electricity produced and distributed in multiples of 11. 440V, 11KV, 22KV, 132KV etc

2 Answers   Bhel,

is it possible to have dc motors on single chip

0 Answers  

How will u calculate wire size according to current rating?

2 Answers   Global Computer,

whay we used silica gel in Transformer

3 Answers  

A shopkeeper allows 10% discount on the price of an article and sells it for Rs 7,600. What is the marked price of the article?

1 Answers  

What will happen if power transformer designed for 50 Hz is connected to 500 Hz of the same voltage , and vice versa ?

1 Answers