JEE Main 2026 — Current Electricity Question with Solution
JEE Main 2026 (28 January Shift 2)
Question
Which one of the following is not a measurable quantity?
Choose an option
Show full solutionCorrect option: A
Correct answer
AVoltage
Step-by-step explanation
In electrostatics and circuit theory, potential (voltage) at a single point is defined relative to a reference point (usually infinity or ground where potential is assumed to be zero).
Absolute voltage at a point is not a physically measurable quantity because only the difference in potential between two points can be measured using instruments like a voltmeter.
Resistance can be measured using an ohmmeter or bridge circuits.
Displacement current is a physical quantity that can be calculated and its effects (magnetic field) can be measured.
Voltage difference (potential difference) is the standard quantity measured between two points in a circuit.
Therefore, absolute voltage is not a measurable quantity.
Absolute voltage at a point is not a physically measurable quantity because only the difference in potential between two points can be measured using instruments like a voltmeter.
Resistance can be measured using an ohmmeter or bridge circuits.
Displacement current is a physical quantity that can be calculated and its effects (magnetic field) can be measured.
Voltage difference (potential difference) is the standard quantity measured between two points in a circuit.
Therefore, absolute voltage is not a measurable quantity.
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This is a previous-year question from JEE Main 2026, covering the Current Electricity chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.