The voltmeter is connected in parallel with the component. The supply voltage is shared between components in a series circuit, so the sum of the voltages across all of the components in a series ...

Also, you might not want to keep the voltmeter constantly connected in parallel in the circuit. You might need the voltmeter for testing many different circuits. You don't want the behavior of a ...

Voltage is measured in volts, V, with a voltmeter. Voltmeters are always connected in parallel. This is because it is measuring the difference in energy between the two points it is connected across.