Home > 0877 > GR0877 Problem 42

## GR0877 Problem 42

PROBLEM STATEMENT: This problem is still being typed.

SOLUTION: (E) From the picture we see that the period of oscillations (this is $2\pi$ phase difference) is approximately 6 cm, while the difference between two points of equal voltage-level (say, zero-level) for two waveforms is 2 cm. Thus, the phase difference between waveforms is $2 \cdot 2 \pi/6 = 2\pi/3$.

Found a typo? Comment!

 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100

Want to get a full PDF with solutions? Read THIS.

The comments appending particular solutions are due to the respective users. Educational Testing Service, ETS, the ETS logo, Graduate Record Examinations, and GRE are registered trademarks of Educational Testing Service. The examination questions are © 2008 by ETS.

Categories: 0877 Tags: , , , ,
1. 08.11.2011 at 14:36

How do you know it’s 120 and not 90?

2. 11.11.2011 at 17:37

So, there are 3 squares for every 90 degrees. If you look at the shift in Channel 2 to the right, you end up with ~4 squares difference, which implies 4/3*90=120. If you shift it to the left, you need to by ~2, so that 2/3*90 = 60.

Is there some reason why it couldn’t be 60?

• 12.11.2011 at 16:47

mark :

So, there are 3 squares for every 90 degrees.

Wrong. 180 degrees.

3. 12.11.2011 at 16:50

DB :

How do you know it’s 120 and not 90?

Well, did you read the solution (carefully)? I think it’s clear.