A rheostat is a device which is used to vary the resistance in an electrical circuit without interrupting the circuit.heostats are a kind of potentiometer. These devices can be used in a variety of settings, and are usually designed to be sealed so that environmental factors cannot interfere with the function of the circuit.
This chemical can cause allergic rhinitis and its symptoms, including a runny nose, sneezing, and itchy eyes. In addition to tree pollen, other common allergens include: grass pollen
Common symptoms of allergic rhinitis include: 1  sneezing. 2  a runny nose. 3  a stuffy nose.  an itchy 1  nose. coughing.  a sore or scratchy 1  throat. itchy 2  eyes. watery  eyes. dark circles under 1  the eyes. frequent headaches.  eczema-type symptoms, such as having extremely dry, itchy skin that often 1  blisters. hives. excessive  fatigue.