How does a potentiometer differ from rheostat?

Answer 1

potentiometer has 3 pins while rheostat contains only 2 pins..

Answer 2

The function of potentiometer is to divide voltage in a circuit where as a rheostat is a variable resistance to change the current in a circuit. A potentiometer can of course be used as a rheostat by using only one fixed terminal and the slider, leaving the other terminal unconnected.

Answer 3

1. Potentiometer:

A potentiometer is a variable resistor that can be used as a voltage divider.

Originally a potentiometer was an instrument to measure the potential (or voltage) in a circuit by tapping off a fraction of a known voltage from a resistive slide wire and comparing it with the unknown voltage by means of a galvanometer.

Usually, this is a three-terminal resistor with a sliding contact in the center (the wiper). If all three terminals are used, it can act as a variable voltage divider. If only two terminals are used (one side and the wiper), it acts as a variable resistor. Its shortcoming is that of corrosion or wearing of the sliding contact, especially if it is kept in one position.

Potentiometers used to control high power are normally called rheostats.

2. Rheostat:

A rheostat is essentially a potentiometer, but is usually much larger, designed to handle much higher voltage and current. Typically these are constructed as a resistive wire wrapped to form a toroid coil (or most of one) with the wiper moving over the upper surface of the toroid, sliding from one turn of the wire to the next. Sometimes a rheostat is made from resistance wire wound on a heat resisting cylinder with the slider made from a number of metal fingers that grip lightly onto a small portion of the turns of resistance wire. The 'fingers' can be moved along the coil of resistance wire by a sliding knob thus changing the 'tapping' point. They are usually used as variable resistors rather than variable potential dividers.

Answer 4

A potentiometer has three terminals. A rheostat (which is an ancient name for a variable resistor that can handle a fair bit of current) only needs two terminals. The point is that with a potentiometer, you can vary the applied voltage from the supply voltage all the way down to zero. You can't do that with a rheostat. You can vary the voltage applied to the component from the supply voltage down to some value determined by the ratio of the component's resistance to the maximum resistance of the rheostat. The current through a potentiometer does not stay the same. The current that you are putting through the component has to come from somewhere! Best wishes for your test.

Answer 5

Usually potentiometers designed to control higher powers are called rheostats. The essential functionality is the same.

Answer 6

FIRST OF ALL , A POTENTIOMETER IS USED TO MEASURE THE POTENTIAL,AND RHEOSTAT IS USED TO MEASURE RESISTANCE.AND OFCOURSE, THE MAJOR DIFFERENCE IS THEIR SPELLINGS