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%.
An ideal voltmeter has two terminals and senses the voltage between the terminals where they may be connected to a circuit. Ideally the voltmeter has infinite resistance. It is polarized and indicates polarity as well as the magnitude of the voltage. An ideal ammeter is a two terminal device, also polarized. It is connected in series with circuit elements to measure the sign and magnitude of the current flowing through that component. The circuit has to be opened to insert the ammeter to measure current flow. The ideal ammeter has no resistance to flow.