Question about Blackbox testing procedure

[Slayerza]

Hi,
Suppose that you have a black box with 2 terminals (+/-) and are required to measure the voltage. In order to be sure two people simultaneously attach volt meters to the terminals.

Question
Why does the two meters not measure the same voltage? Assuming ofcourse that the meters are both functional and correctly calibrated.

Cheers
Slayer

 

[dspman]

Blackbox testing

Hi,

Is it an IQ test?
They my connected the voltmeters reverced. I mean that i.e. the first man connected + connection to port 1 and - connection to port 2 and the other is connected them reversed. so the voltmeters show +V and -V.
Is it correct?

 

[sivakumar_tumma]

Re: Blackbox testing

Hi,
Suppose that you have a black box with 2 terminals (+/-) and are required to measure the voltage. In order to be sure two people simultaneously attach volt meters to the terminals.

Question
Why does the two meters not measure the same voltage? Assuming ofcourse that the meters are both functional and correctly calibrated.

Cheers
Slayer

I am thinkinglike this....

Each pweron have different electrical equivalent capacitance. when two pwople hols voltmeter sumulataneoulsy, the equavalent capcitance of human being is different for two people. SO the current flowing though ground for two people will be different. So the voltmeter measure different voltages even though they are connected in parallel across same two terminals....

tell me if u get some other expalnation..........

 

[Slayerza]

Re: Blackbox testing

Hi,
Personally I don't have the answer yet, but have observed this and was windering how it could be possible. I am yet to find the corect (if only one) answer.

Cheers
Slayer