Question

Why are measured voltages smaller than theoretical?

Answer 1

Some of the common glitches may be which cause variation changes are:

1. The ammeter isn't calibrated correctly.
2. The readings might be off.
3. The voltage variation may be because of making a note of the wrong reading. For example, you note 10 volts theoretically, but it is only 9.3 volts under load.
4. In an analog ammeter, there is a parallax error in reading the meter which pitches off the main measurement.
5. There might be a loose connection.