The correct answer is: A rheostat differs from potentiometer in the respect that it has lower wattage rating.
A rheostat is a variable resistor that is used to control the amount of current in a circuit. It has two terminals, and the resistance between the terminals can be changed by moving a sliding contact. A potentiometer is also a variable resistor, but it has three terminals. The resistance between any two terminals can be changed, and the middle terminal is always at a fixed voltage.
Rheostats are typically used to control the speed of motors, the brightness of lights, and the temperature of heaters. Potentiometers are typically used to create voltage dividers, to measure voltage, and to calibrate other instruments.
The main difference between a rheostat and a potentiometer is the wattage rating. A rheostat has a lower wattage rating than a potentiometer. This means that a rheostat can only handle a smaller amount of current before it overheats and fails.
The other options are not correct. A rheostat does not necessarily have a higher wattage rating than a potentiometer. A rheostat does not necessarily have a large number of turns. A rheostat does not necessarily offer a large number of tapping.