An operational amplifier will always output a voltage that is exactly equal to the difference between its two input voltages, regardless of its power supply limitations.

The statement is false because an op‑amp’s output can only swing between its supply rails, so if the calculated difference exceeds those rails the output saturates at the rail voltage. In practice, the op‑amp first amplifies the difference, but if the result would be higher than the positive rail or lower than the negative rail, the output simply clamps at the rail value. For example, with a ±15 V supply, an input difference that would require a 20 V output will instead produce a 15 V output, and a difference that would need –20 V will produce –15 V. Thus, the op‑amp can only deliver the difference up to the limits set by its power supply, and any attempt to exceed those limits results in output saturation.