The device used for measuring potential difference across the ends of a conductor is:

Correct option is B

The correct answer is (b) Voltmeter

Explanation:

• Potential difference (Voltage, V) is the difference in electric potential between two points in a circuit.
• The Voltmeter is a device specifically designed to measure this potential difference.
• A Voltmeter is always connected in parallel across the component whose voltage needs to be measured because:
• It has high resistance, preventing current from passing through it.
• It ensures that the full potential difference is measured without significantly affecting the circuit.

Information Booster:

• SI Unit of Potential Difference: Volt (V)
  
• Formula: V=IR
• where:
• V = Potential Difference (Volts)
• I = Current (Amperes)
• R = Resistance (Ohms)

Additional Knowledge:

Galvanometer

• A device used to detect and measure small electric currents.
• Works on the principle of electromagnetic induction (interaction of current with a magnetic field).
• Consists of a coil suspended in a magnetic field; deflection indicates current flow.
• Uses: Measuring minute currents in circuits, forming the basis for ammeters and voltmeters.

Ammeter

• The instrument used to measure electric current (in amperes) in a circuit.
• Connected in series in a circuit to measure current without significantly affecting it.
• Conversion: A galvanometer can be converted into an ammeter by adding a low-resistance shunt parallel to it.