Mark-space ratio for 25 kHz pulse with 4 μs period

[engnrshyckh]

<Moderator's note: Moved from a technical forum and therefore no template, which would have helped a lot in this case ...>

i know that mark time is duration in which a pulse is present and space time is a duration is which pulse is not present. my attempt to ques is: f= 25000Hz...> t=1/f=0.4us which means pulse is present for 0.4us. that is mark time is .4us. space time 4-0.4=3.6us s therefore:
Mark:space= 0.4:3.6
=4:36,,,...>1:9 please tell me if i my calculation is faulty. Also what will be mark to Phase ratio

 

[Asymptotic]

The period of a complete cycle is the reciprocal of frequency.

 

[engnrshyckh]

The period of a complete cycle is the reciprocal of frequency.

25000hz leads to 0.4us not 4us so something is missing :P

 

[Asymptotic]

25000hz leads to 0.4us not 4us so something is missing :P

1/25 KHz = 1/25 ms. 1/25 ms = 0.04 ms.
0.04 ms = 40 μs total period.
Total time = Mark time + Space time

space time 4-0.4=3.6us

Where did the 4 μs value come from?

How is this "mark to phase ratio" defined? It's new terminology to me.

 

[engnrshyckh]

1/25 KHz = 1/25 ms. 1/25 ms = 0.04 ms.
0.04 ms = 40 μs total period.
Total time = Mark time + Space timeWhere did the 4 μs value come from?

How is this "mark to phase ratio" defined? It's new terminology to me.

4us is given in question... if i simplify the question then i want to find mark to space and mark to phase ratio given the frequency and time period. i havnt either heard about the letter

 

[Asymptotic]

If a single cycle of the waveform is 40 μs wide, and the mark time is 4 μs wide, then what is the duration of the 'space'?