Which One Is Lying: Multimeter Or Voltage Tester? Why?

First off you should be checking for voltage with the voltmeter with one lead on the black wire and one lead on the white wire..the voltmeter should read 120 volts /-10% if it does then that is what it should read...If you check with a voltmeter with one lead on the black wire and one lead to ground you still should read 120 volts /- 10% as long as you do not have an isolated ground for the system. ..now with one lead on the white wire and one lead to ground you should not read any voltage with the voltmeter... I always use a Simpson 260 voltmeter to tets for voltage ,ohms ,or contunity.. I have never ever used any other kind of voltage tester other than some good digital voltmeter.

1. If the function/range switch is set at 200 VAC, what will the multimeter read if a measurement is made directl?

A. 0 volts. At least theoretically. If there is current flowing in the circuit connected to the fuse, you may measure a tiny PD across a good fuse due to its resistance. You should also read 0 volts across a blown fuse if the load is DISconnected. If the load is connected and the fuse is blown/ breaker has tripped, you will measure 120V.

2. Analog multimeter won't calibrate to zero

Analog meters can get knocked out of whack from being banged around or a modest drop. It may need a trip to the repair shop. A cost conscious move might dictate a replacement is in order

3. Why is resistance increasing while I'm measuring using a multimeter?

The question which led me here was in regard to the increasing resistance of an agarose gel petri dish over time. As suggested by Olin, I tried changing my electrodes from copper to another material, but saw no difference.After some more research, and taking into consideration that agarose gel contains salt ions which carry the current, it is likely that the Ohmmeter is in a way depleting the ions available for conductance since they have been drawn to their respective poles.

4. Can I use 1 to 2 power adaptor to measure current with multimeter

No this is not possible with a standard multi-outlet adapter. They are wired so that all outlets are in parallel. So you could measure voltage but not current, as you need a series connection to measure current. There are specialized measurement adapters available which allow you to measure both, current and voltage and with the right tools you can measure power then

5. Multimeter shows different voltages for positive and negative voltage(interchanging multimeter probes) for same source

Different positive and negative readings on a dual-slope ADC can be caused by the maker using a crummy integrating capacitor with a large amount of dielectric absorption. It's also possible the battery is dying and the integrator is saturating on one side but not the other. Your other issue sounds like a grounding problem.

6. Blown fuse on car by using multimeter

The other possibility is that with the probe you touched earth or ground at the same time as the live terminal or wire - sometimes making a small probe extension is good. I have used a paper clip before

7. How do you test a 30 amp RV outlet with a multimeter?

Set the meter at AC volts. Insert the two multi meter leads into the 2 slotted holes in the outlet. The amperage is irrelevant. The meter will only test for voltage. If you want to test for amps, you'll need an amp clamp.How do you test a 30 amp RV outlet with a multimeter?.

8. kv to volts using multimeter?

Impossible! You could change the pulsed DC voltage to a more steady voltage using capacitors, but you can not measure kVolts on a device that only measures upto 500V. If you are a real smart guy you could use resistors in series to lower the measured voltage, and from there calculate how much volt the pulses are, but that would require some thorough knowledge in electric theory (formula's and methods to calculate)