Voltage and Current - Technical MCQs

Q1:

A rheostat is ___.

A a three-terminal device that controls current

B a two-terminal device that controls current

C a two-terminal device that divides voltage

D a three-terminal device that divides voltage

ANS:B - a two-terminal device that controls current

Rheostat is an adjustable or variable resistor. It is used to control the electrical resistance of a circuit without interrupting the flow of current. Rheostat has 3 terminals and usually consist of a resistive wire wrapped to form a toroid coil with a wiper that slides along the surface of the coil. It is most often designed with a ceramic core. Rheostats are used in applications that require high voltage and current.