A structure or part that is enclosed within its own membrane inside a cell and has a particular function. Organelles are found only in eukaryotic cells and are absent from the cells of prokaryotes like bacteria.The nucleus, mitochondrion, and chloroplast are examples of organelles.rÂ·ganÂ·elle. n. A differentiated structure within a cell, such as a mitochondrion, vacuole, or chloroplast, that performs a specific function. [New Latin. , diminutive of Medieval Latin.
A voltmeter is an instrument used for measuring electrical potential difference between two points in an electric circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage of the circuit; digital voltmeters give a numerical display of voltage by use of an analog to digital converter.Voltmeters are made in a wide range of styles.eneral purpose analog voltmeters may have an accuracy of a few percent of full scale, and are used with voltages from a fraction of a volt to several thousand volts. Digital meters can be made with high accuracy, typically better than 1%.
Instruments for measuring voltages include the voltmeter, the potentiometer, and the oscilloscope. The voltmeter works by measuring the current through a fixed resistor, which, according to Ohm's Law, is proportional to the voltage across the resistor.