A DC motor generates power when it is rotating even when no supply is connected.
Voltmeter.Current and voltage are two different things. They are closely related but a current does not imply a voltage and nor does a voltage imply a current.A volt meter is used to measure a voltage. The voltage may be across a battery or other power source. It may be across a component such as a resistor or a group of components. If a current is flowing through a resistor, there will be a voltage across the resistor. Similarly, if there is a voltage across a resistor, there will be a current flowing.Current is measured using an ammeter - Current is measured in amps, hence the name of the meter.The two meters together can be used to analyze most electronic circuits and they are the two most important items of test equipment in electronics. Devices called multi-meters are combined ammeters and voltmeters and are in every electronics engineer's toolbox.
In series and across the load are contradictory statements. Some voltmeters are really capable of voltage, current and resistance measurements. To measure current the meter either has to be a clamp on type or one that goes in series with the load. You measure voltage drop across the load as described above.
In a DC circuit, just connect your meter across the source or electrical bus. The meter, because it is one of the newer digital ones, will work regardless of which way the leads are connected. If the leads are plugged into the meter correctly, the investigator need only look at the sign associated with the reading on the meter and the position of the leads. If the reading on the meter is "13.6 V" on a DC setting, then the red lead is connected to the positive side or negative rail, and the black to the negative side or negative rail. Conversely, if the reading is "-13.6 V" on a DC setting, the red lead is on the negative side or negative rail, and the black lead is on the positive side or positive rail. The DMM is a wonderful innovation and will allow someone making measurements to not have to worry about which way to connect the leads - as long as that someone pays attention to the sign displayed with the voltage reading.
with a resistor 300K in series with the 50 micro amperes DC meter
A hand held test meter is usually rated for 1000 volts.
The main cause for a meter to read negative voltage across a DC motor is a loose ground wire. The ground wire can be loose or may need to be cleaned.
A DC motor generates power when it is rotating even when no supply is connected.
The source voltage.
Because the meter is connected backwards
A: Current flow only one way form positive to a less positive point. However it is possible to measure negative and positive voltage drop it the meter leads are reversed.
This is important when meter cannot display negative values, e.g. it is analogous meter with scale. Most digital meters can display negative values. P.S. I am amateur in elecrtonics.
When connecting a volt meter to a light bulb to measure the voltage of the light bulb, run a third wire from where the wire enters the bulb to one terminal of the voltmeter and a fourth wire from the other side of the bulb to the other terminal of the voltmeter.
To measure electrical voltage accurately using a volt meter, first ensure the meter is set to the appropriate voltage range. Connect the red probe to the positive terminal and the black probe to the negative terminal of the circuit. Read the voltage displayed on the meter and record the measurement.
You measure current by inserting an amp meter in series with the circuit or using a clamp-on meter to measure current by induction. You measure voltage with a volt meter across the supply. You measure resistance in ohms across the resistance. Luckily all these functions are in the same meter in most cases.
Putting capacitors in series and then applying a DC voltage to them is not entirely useful. The voltage will cause a small current to flow into the capacitors, charging them to a total cumulative voltage of 200V. No further current will flow. If a meter is applied to one of the capacitors it's charge will cause a voltage measurement but it will quickly drop as the current flowing into the meter discharges the capacitor.
Simply set the multi meter on DC voltage, which is denoted by a line with dotted lines under it. Then place the red lead on the positive side of the bulb and the black lead on the negative side. If you do this incorrectly it will be a negative number but the same number if the leads are reversed. If you have a bad bulb the meter will show all zero´s. Otherwise you´ll get something like 0.01 which is a good indicator for a working bulb. The voltage across the light bulb will be the same voltage as the supply. Regardless of whether the bulb is good or bad the voltage potential will still be there. You are measuring voltage not amperage.
An analogue meter will deflect the needle the wrong way. A digital meter will show a negative value.