Question 254Electricity & Electronics - QMED

The correct answer is C) Ward-Leonard. The Ward-Leonard method is a speed control system for DC motors that uses a generator and a series-connected field rheostat to control the motor's field current and thereby its speed. This method was commonly used for DC motor speed control in the early to mid-20th century, including in various marine applications like those found on US Coast Guard vessels. The other options are incorrect because they do not refer to a DC motor speed control method. Burmeister-Wain, Atlas-Copco, and Sperry-Rand are the names of companies or products, not the specific speed control technique depicted in the illustration.