Calm down dear â itâs only a formula!! This tells us how many atoms, and how many types of atoms can be found in a particular. chemical. For instance, if we use a periodic table we can see that Ca stands for calcium, and as. there is no number after Ca we know a molecule of this chemical contains only 1 calcium atom. The period table also shows us that C stands for Carbon, so there must be one carbon atom in. this molecule.
The correct term for the common terminal of a potentiometer is the slider. A rheostat is simply a variable resistance used to control power to a load and you are correct about the wiring. Only the slider and one other terminal are used. A potentiometer uses all three terminals, enabling a variable voltage or signal to be tapped off from the slider.
Transcutaneous electrical nerve stimulation (TENS) is a method of pain relief involving the use of a mild electrical current. A TENS machine is a small, battery-operated device that has leads connected to sticky pads called electrodes. You attach the pads directly to your skin. When the machine is switched on, small electrical impulses are delivered to the affected area of your body, which you feel as a tingling sensation.