Loading ...
Sorry, an error occurred while loading the content.

Re: Low pass filter question

Expand Messages
  • Keith
    ... The book is wrong. It won t be the first time - many of my text have mistakes in them and given you are trying to learn from them it is annoying that
    Message 1 of 12 , May 1, 2004
    • 0 Attachment
      --- In Electronics_101@yahoogroups.com, "upand_at_them"
      <upand_at_them@y...> wrote:
      > Well, that's what I thought the answer was, too. But the book said
      > it was (a).
      >

      The book is wrong. It won't be the first time - many of my text have
      mistakes in them and given you are trying to learn from them it is
      annoying that simple tryping mistakes get through.

      Keith.
    • Scott Thompson
      I was assuming they were talking about sinusoidal analysis. Peace, Scotty ... From: Roy J. Tellason To: Electronics_101@yahoogroups.com Sent: 4/30/2004
      Message 2 of 12 , May 1, 2004
      • 0 Attachment
        I was assuming they were talking about sinusoidal analysis.
         
        Peace,
        Scotty
         
         
        ----- Original Message -----
        Sent: 4/30/2004 20:28:14
        Subject: Re: [Electronics_101] Low pass filter question

        On Friday 30 April 2004 09:24 pm, Scott Thompson wrote:
        > (d) is correct because the low-pass filter passes all frequencies below its
        > corner frequency (at which point the signal drops to 70.7% of its original
        > value, or -3 dB).  Since 1 kHz is ten times below 10 kHz, it is expected
        > that the low-pass filter will pass this signal unchanged.

        Only if that input signal is a pure fundamental,  and doesn't contain any
        harmonics whatsoever...

        > ----- Original Message -----
        > From: upand_at_them
        > To: Electronics_101@yahoogroups.com
        > Sent: 4/30/2004 17:14:26
        > Subject: [Electronics_101] Low pass filter question
        >
        >
        > I was going through an electronics book this week.  And at the end of
        > the chapter on filters there was a short quiz.  I got this question
        > wrong, but I don't know why:
        >
        > A signal of frequency 1 kHz is applied to a low-pass filter with a
        > corner frequency of 10 kHz.  What happens?
        >
        > a. The output signal is one-tenth of the input signal.
        > b. The output signal is larger than the input signal.
        > c. There is no output signal.
        > d. The output signal is identical to the input signal.
        > e. All of these.
        >
        > Which is correct?
        >
        > Mike
        >
        >
        >
        >
        >
        >
        > Yahoo! Groups Links
        >
        > To visit your group on the web, go to:
        > http://groups.yahoo.com/group/Electronics_101/
        >
        > To unsubscribe from this group, send an email to:
        > Electronics_101-unsubscribe@yahoogroups.com
        >
        > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

      • Dave Mucha
        ... said ... have ... The best answer I have seen to this question of is the book wrong is to prove why is CAN work that way, then why it CANNOT work that
        Message 3 of 12 , May 1, 2004
        • 0 Attachment
          --- In Electronics_101@yahoogroups.com, "Keith" <keith@k...> wrote:
          > --- In Electronics_101@yahoogroups.com, "upand_at_them"
          > <upand_at_them@y...> wrote:
          > > Well, that's what I thought the answer was, too. But the book
          said
          > > it was (a).
          > >
          >
          > The book is wrong. It won't be the first time - many of my text
          have
          > mistakes in them and given you are trying to learn from them it is
          > annoying that simple tryping mistakes get through.
          >
          > Keith.

          The best answer I have seen to this question of "is the book wrong"
          is to prove why is CAN work that way, then why it CANNOT work that
          way.

          go back and forth and if you unhderstnd the subject and the question,
          then you will confirm the correct answer.

          If the question is worded in such a way as to have two possible
          answers, then you will have confidence in BOTH answers.


          a both answer question might be "can you build an automobile"
          Chances are, given the time and money you CAN, but with your current
          projects you cannot. Both answers are correct.


          Therefore
          Step #1 review the question to make sure you understand EXACTLY what
          it means. NOT what you THINK it means, and that can be a BIG
          difference.

          Step #2, try to prove it works the way the author says.
          Step #2a, try to prove it does not work the way the author says.

          Once you do those simple steps you have confidence in your answer.
          If you realize you don't know enough to prove or disprove, then the
          triumph for you is that you narrowed down the tiny bit of information
          you didn't get from the subject.

          Dave
        • Steve
          So I m not the only one who reads way too much into test questions. I remember tests that I would have aced but I got a couple wrong because I read too much
          Message 4 of 12 , May 1, 2004
          • 0 Attachment
            So I'm not the only one who reads way too much into test questions. I
            remember tests that I would have aced but I got a couple wrong because
            I read too much into the question.

            ;')

            D is definitely the correct answer. The book is wrong, or the question
            was not relayed accurately. A filter can have a gain other than 1.

            Alien Steve

            --- In Electronics_101@yahoogroups.com, "Scott Thompson"
            <electronguy@e...> wrote:
            > I was assuming they were talking about sinusoidal analysis.
            >
            > Peace,
            > Scotty
            >
            >
            > ----- Original Message -----
            > From: Roy J. Tellason
            > To: Electronics_101@yahoogroups.com
            > Sent: 4/30/2004 20:28:14
            > Subject: Re: [Electronics_101] Low pass filter question
            >
            >
            > On Friday 30 April 2004 09:24 pm, Scott Thompson wrote:
            > > (d) is correct because the low-pass filter passes all frequencies
            below its
            > > corner frequency (at which point the signal drops to 70.7% of its
            original
            > > value, or -3 dB). Since 1 kHz is ten times below 10 kHz, it is
            expected
            > > that the low-pass filter will pass this signal unchanged.
            >
            > Only if that input signal is a pure fundamental, and doesn't
            contain any
            > harmonics whatsoever...
            >
            > > ----- Original Message -----
            > > From: upand_at_them
            > > To: Electronics_101@yahoogroups.com
            > > Sent: 4/30/2004 17:14:26
            > > Subject: [Electronics_101] Low pass filter question
            > >
            > >
            > > I was going through an electronics book this week. And at the end of
            > > the chapter on filters there was a short quiz. I got this question
            > > wrong, but I don't know why:
            > >
            > > A signal of frequency 1 kHz is applied to a low-pass filter with a
            > > corner frequency of 10 kHz. What happens?
            > >
            > > a. The output signal is one-tenth of the input signal.
            > > b. The output signal is larger than the input signal.
            > > c. There is no output signal.
            > > d. The output signal is identical to the input signal.
            > > e. All of these.
            > >
            > > Which is correct?
            > >
            > > Mike
          • Roy J. Tellason
            ... Gotta watch out for those assumptiosn, they ll jump out and bite you in the rear end every time... :-)
            Message 5 of 12 , May 1, 2004
            • 0 Attachment
              On Saturday 01 May 2004 10:54 am, Scott Thompson wrote:
              > I was assuming they were talking about sinusoidal analysis.

              Gotta watch out for those assumptiosn, they'll jump out and bite you in the
              rear end every time... :-)


              > Peace,
              > Scotty
              >
              >
              > ----- Original Message -----
              > From: Roy J. Tellason
              > To: Electronics_101@yahoogroups.com
              > Sent: 4/30/2004 20:28:14
              > Subject: Re: [Electronics_101] Low pass filter question
              >
              > On Friday 30 April 2004 09:24 pm, Scott Thompson wrote:
              > > (d) is correct because the low-pass filter passes all frequencies below
              > > its corner frequency (at which point the signal drops to 70.7% of its
              > > original value, or -3 dB). Since 1 kHz is ten times below 10 kHz, it is
              > > expected that the low-pass filter will pass this signal unchanged.
              >
              > Only if that input signal is a pure fundamental, and doesn't contain any
              > harmonics whatsoever...
              >
              > > ----- Original Message -----
              > > From: upand_at_them
              > > To: Electronics_101@yahoogroups.com
              > > Sent: 4/30/2004 17:14:26
              > > Subject: [Electronics_101] Low pass filter question
              > >
              > >
              > > I was going through an electronics book this week. And at the end of
              > > the chapter on filters there was a short quiz. I got this question
              > > wrong, but I don't know why:
              > >
              > > A signal of frequency 1 kHz is applied to a low-pass filter with a
              > > corner frequency of 10 kHz. What happens?
              > >
              > > a. The output signal is one-tenth of the input signal.
              > > b. The output signal is larger than the input signal.
              > > c. There is no output signal.
              > > d. The output signal is identical to the input signal.
              > > e. All of these.
              > >
              > > Which is correct?
              > >
              > > Mike
              > >
              > >
              > >
              > >
              > >
              > >
              > > Yahoo! Groups Links
              > >
              > > To visit your group on the web, go to:
              > > http://groups.yahoo.com/group/Electronics_101/
              > >
              > > To unsubscribe from this group, send an email to:
              > > Electronics_101-unsubscribe@yahoogroups.com
              > >
              > > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
              >
              > Yahoo! Groups Links
              >
              > To visit your group on the web, go to:
              > http://groups.yahoo.com/group/Electronics_101/
              >
              > To unsubscribe from this group, send an email to:
              > Electronics_101-unsubscribe@yahoogroups.com
              >
              > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
            • Dave Mucha
              ... I ... because ... question ... There you go then. There is no way to get any other answer to work, except in some special cases, and since the question was
              Message 6 of 12 , May 1, 2004
              • 0 Attachment
                --- In Electronics_101@yahoogroups.com, "Steve" <alienrelics@y...>
                wrote:
                > So I'm not the only one who reads way too much into test questions.
                I
                > remember tests that I would have aced but I got a couple wrong
                because
                > I read too much into the question.
                >
                > ;')
                >
                > D is definitely the correct answer. The book is wrong, or the
                question
                > was not relayed accurately. A filter can have a gain other than 1.
                >
                > Alien Steve


                There you go then.

                There is no way to get any other answer to work, except in some
                special cases, and since the question was not asking HOW or WHY some
                other result could occur, D is the only choice.

                D is the correct answer.





                >
                > --- In Electronics_101@yahoogroups.com, "Scott Thompson"
                > <electronguy@e...> wrote:
                > > I was assuming they were talking about sinusoidal analysis.
                > >
                > > Peace,
                > > Scotty
                > >
                > >
                > > ----- Original Message -----
                > > From: Roy J. Tellason
                > > To: Electronics_101@yahoogroups.com
                > > Sent: 4/30/2004 20:28:14
                > > Subject: Re: [Electronics_101] Low pass filter question
                > >
                > >
                > > On Friday 30 April 2004 09:24 pm, Scott Thompson wrote:
                > > > (d) is correct because the low-pass filter passes all
                frequencies
                > below its
                > > > corner frequency (at which point the signal drops to 70.7% of
                its
                > original
                > > > value, or -3 dB). Since 1 kHz is ten times below 10 kHz, it is
                > expected
                > > > that the low-pass filter will pass this signal unchanged.
                > >
                > > Only if that input signal is a pure fundamental, and doesn't
                > contain any
                > > harmonics whatsoever...
                > >
                > > > ----- Original Message -----
                > > > From: upand_at_them
                > > > To: Electronics_101@yahoogroups.com
                > > > Sent: 4/30/2004 17:14:26
                > > > Subject: [Electronics_101] Low pass filter question
                > > >
                > > >
                > > > I was going through an electronics book this week. And at the
                end of
                > > > the chapter on filters there was a short quiz. I got this
                question
                > > > wrong, but I don't know why:
                > > >
                > > > A signal of frequency 1 kHz is applied to a low-pass filter
                with a
                > > > corner frequency of 10 kHz. What happens?
                > > >
                > > > a. The output signal is one-tenth of the input signal.
                > > > b. The output signal is larger than the input signal.
                > > > c. There is no output signal.
                > > > d. The output signal is identical to the input signal.
                > > > e. All of these.
                > > >
                > > > Which is correct?
                > > >
                > > > Mike
              Your message has been successfully submitted and would be delivered to recipients shortly.