How to create a wattmeter

Question: What type of basic meters can be configured as a wattmeter?

Answer:

A wattmeter measures power. Since power is the product of voltage and current, if we have a voltmeter and an ammeter available, these basic meters can be configured to measure power. The ammeter will be connected in series to the circuit element while the voltmeter is connected in parallel to the circuit element.

Why a voltmeter is a high resistance instrument

Question: Why is it necessary that a voltmeter be a high resistance instrument?

Answer:

Since a voltmeter is connected in parallel to a circuit element, it should have a high resistance to prevent current passing through the circuit element from passing through it instead. This ensures an accurate voltmeter reading.

Use of a Series Resistor

Question: What device is used to extend the range of a DC voltmeter and how is it connected to the basic meter?


Answer:

A resistor connected in series to the voltmeter can be used to extend the voltmeter's range.