Which graphs represent different types of current flow?

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jaximus
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Homework Statement


(1) Name the waveform(s) that represent a periodical current flow.

(2) Name the waveform(s) that represent a direct current.

(3) Name the waveform(s) that represent a non-periodical alternating current.

(4) Name the waveform(s) that represent a current with a non-positive average

Each letter can be used more than once or not at all. I find some graphs to be very tricky and confusing. For example, graph A looks like a direct current graph but it goes below the 0 line a little, causing me to doubt it. Graph E and G are very weird graphs for me as well.

Homework Equations


No calculations required. Question only requires me to choose which graph fits which description.

The Attempt at a Solution


My answers: 1) C, A, D
2) D, F
3) B, E, G
4) E
 
Attachments
  • Seven labelled current-versus-time graphs, A to G, with dashed reference lines: A and D are triangular waves, B is a pulse train, C is a sine wave about zero, E and G are irregular wiggles, F is a wavy curve, and G rises steadily.
    Screenshot_5.png
    20.7 KB · Views: 416

Discussion

jaximus said:

Homework Statement


Seven small graphs labelled A to G plotting current against time, with dashed horizontal reference lines; A is a triangle wave between about 1 and 2, B a rectangular pulse train, C a sine wave, D a triangle wave between 5 and 10, E an irregular noisy trace, F an irregular trace between 3 and 6, G a rising noisy trace.

(1) Name the waveform(s) that represent a periodical current flow.

(2) Name the waveform(s) that represent a direct current.

(3) Name the waveform(s) that represent a non-periodical alternating current.

(4) Name the waveform(s) that represent a current with a non-positive average

Each letter can be used more than once or not at all. I find some graphs to be very tricky and confusing. For example, graph A looks like a direct current graph but it goes below the 0 line a little, causing me to doubt it. Graph E and G are very weird graphs for me as well.

Homework Equations


No calculations required. Question only requires me to choose which graph fits which description.

The Attempt at a Solution


My answers: 1) C, A, D
2) D, F
3) B, E, G
4) E
Hello, @jaximus . Welcome to PF.

You did well to use the "UPLOAD" feature for your image.
I find it helpful for the full image to be shown in the post rather than just showing the thumbnail image, but other helpers may disagree with me.

As for your answers, I agree with all but 4), which should have one additional selection.
 
Attachments
  • Seven small graphs labelled A to G plotting current against time, with dashed horizontal reference lines; A is a triangle wave between about 1 and 2, B a rectangular pulse train, C a sine wave, D a triangle wave between 5 and 10, E an irregular noisy trace, F an irregular trace between 3 and 6, G a rising noisy trace.
    screenshot_5-png[1].png
    20.7 KB · Views: 348
SammyS said:
Hello, @jaximus . Welcome to PF.

You did well to use the "UPLOAD" feature for your image.
I find it helpful for the full image to be shown in the post rather than just showing the thumbnail image, but other helpers may disagree with me.

As for your answers, I agree with all but 4), which should have one additional selection.
Alright, I'll keep that in mind. Thank you for the advice SammyS.
 
jaximus said:
Alright, I'll keep that in mind. Thank you for the advice SammyS.
OK.

As for answer 4.

If an average is zero, then it is non-negative, right?
 
SammyS said:
OK.

As for answer 4.

If an average is zero, then it is non-negative, right?
Ah yes, it should be. Then number 4 will include graph C since it has an average of 0. Thank you for the lead.
 
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