- power
**1.**In*optics*, the*refractive**vergence*of a*lens*.**2.**In*physics*and*engineering*, the*rate*at which*work*is done.**3.**The exponent of a*number*or*expression*that provides the*number*of times that*number*has to be multiplied by itself.-the effective p. of a*back**vertex*p.*lens*as measured from a*surface*toward the eye; a*standard*for*measurement*of*ophthalmic*lenses.-a*carbon**dioxide*combining p.*measurement*of the total CO_{2}that can be*bound*as HCO_{2}at a PCO_{2}of 40 mmHg at 25°C by*serum*,*plasma*, or whole*blood*.-the p. equal to an infinitely thin*equivalent*p.*lens*as measured on an optical bench.-**resolving p.****1.***definition*of a*lens*; in a*microscope**objective**lens*it is calculated by dividing the*wavelength*of the*light*used by twice the numerical*aperture*of the*objective*. SEE ALSO:*definition*.**2.**analogies to other modalities, e.g., two-point*discrimination*in neurologic*examination*. Commonly misinterpreted as*random**error*, although it has none of its properties.**3.**SYN:*resolution*(2).-**statistical p.**in Neyman-Pearson*hypothesis**testing*, the*probability*of rejecting the null*hypothesis*when it is false; the*complement*of an error of the second kind.* * *Patients Online for Wellness, Education and Research* * *

**pow·er 'pau̇(-ə)r***n***1)**an inherent property or effect*<a drug that enhances the heart's pumping \power*(Kathleen Fackelmann)*>***2)****MAGNIFICATION***(2b)** * *

pow·er (pouґər) [L.*posse*to have power] 1. capability; potency; the ability to act. 2. a measure of magnification, as of a microscope. 3. the rate at which work is done. Symbol*P*. The SI unit of power is the watt. 4. of a statistical test: the probability of correctly rejecting the null hypothesis when a specified alternative holds true; it is equal to 1 minus the probability of a Type II error.

*Medical dictionary.
2011.*