Complex sentence: A potentiometer is an instrument for measuring the potential (or voltage) in a circuit taps off a fraction of a known voltage from a resistive slide wire and compares it with the unknown voltage by means of a galvanometer.
Split into simpler sentences: A potentiometer is an instrument for measuring the potential (or voltage) in a circuit. The instrument taps off a fraction of a known voltage from a resistive slide wire and compares it with the unknown voltage by means of a galvanometer.