Need some help on this questions...

[glenjoy]

1. Explain how you would measure very low resistance in the range of 0.1 ohm accurately.

Ans. Use a kelvin connection across the load, inject a current then read the voltage reading, divide the voltade reading by the current source.

2. Explain how you would measure very high resistance in the range of 10 G ohm accurately.
3. Explain how you would measure very low voltage in the range of 1 n volt accurately.
4. Explain how you would measure very low current in the range of 1 p Amp accurately.
5. Explain why there is a trade off between measuring speed and measuring accuracy.
6. Explain how the impedance of an AA size alkaline battery can be measured easily.
7. Why do we need to have 'impedance matching'?
8. How do you make a Spectrum Analyzer display time domain input?
9. Describe what you would see on the Spectrum Analyzer (with the following settings: centre freq = 1 GHz, Span = 10 Meg Hz, Ref level= 10 dBm) when receiving the following signal from a Vector Signal Generator (with the following settings: freq = 1 GHz, FM on, FM Dev = 1 MegHz, FM rate = 1 Hz, Amplitude = 0 dBm).
10. "Write a LabView program (submit your souce code) to measure voltage and write the data into a file.
a/ use Keithley 2000 multimeter (the user manual with the SCPI commands can be downloaded from www.keithley.com)
b/ set dc measurement range at 100mV
c/ measure 20 readings and write to file"

Thanks.

 

[ptmsl]

2. Use high voltage or a bridge with a known high value resistor
3. use low noise voltage amplifier
4.
5. Tradeoff exists for DC or repetitive signals since integration or repetitive sampling reduces the effect of random noise.
6. measure the current with different loads
7. To remove reflections that can compromise signal integrity and EMI or to maximise power transfer depending on the application