Question

The device used for measuring potential difference is known as :

• A. energy meter
• B. ammeter
• C. galvanometer
• D. voltmeter

Hint:

Remember these common electrical measuring devices:
{Ammeter:} Measures electric {A}mps (Current). Connected in {S}eries.
{Voltmeter:} Measures electric {V}oltage (Potential Difference). Connected in {P}arallel.
{Galvanometer:} Detects small currents; can be a basis for ammeters/voltmeters.
{Energy Meter:} Measures total energy consumed (e.g., kWh).

Answer 1

The Correct Option is D

Concept: Different electrical instruments are designed to measure specific electrical quantities. Potential difference, also known as voltage, is one such quantity. Step 1: Understanding Potential Difference (Voltage) Potential difference (voltage) is the difference in electric potential energy per unit charge between two points in an electric circuit. It is what drives the electric current. Its SI unit is the Volt (V). Step 2: Analyzing the functions of the listed devices
(1) Energy meter (or Watt-hour meter): This device measures the total amount of electrical energy consumed over a period of time. The unit is typically kilowatt-hours (kWh).
(2) Ammeter: An ammeter is an instrument used to measure electric current flowing through a circuit. It is connected in series in the circuit. Its unit is Ampere (A).
(3) Galvanometer: A galvanometer is a sensitive instrument used to {detect} and indicate the presence of small electric currents. It can be modified to make ammeters and voltmeters. On its own, it indicates current, not directly potential difference as a calibrated value.
(4) Voltmeter: A voltmeter is an instrument specifically designed to measure the electric potential difference (voltage) between two points in a circuit. It is connected in parallel across the component or points whose voltage is to be measured. Its unit is Volt (V). Step 3: Identifying the correct device The device used for measuring potential difference (voltage) is the voltmeter.