Question 536Electricity & Electronics - QMED
70% to passAs shown in the illustration, which brush holder is of the reaction type? Illustration EL-0029

A1
B2
C3
D4
AI Explanation
The correct answer is D. The brush holder labeled 4 in the illustration is of the reaction type. The reaction type brush holder is used in DC generators and motors, where the brushes are held in place by a spring that applies pressure against the commutator. This allows the brushes to follow the commutator as it wears down, maintaining constant contact. The other brush holders labeled 1, 2, and 3 are not of the reaction type, as they do not use a spring-loaded mechanism to maintain brush contact with the commutator.
Related Questions
Q236:Capacitors are commonly used on DC power supply circuits for engine room automat... Q97:What happens to the power loss when the current flow through a power transmissio... Q327:Which of the listed meters uses a shunt connected in series with the load, but p... Q207:What type of motor is illustrated by the schematic of figure "B" of the illustra... Q459:What is the primary purpose associated with the use of transformers onboard ship...
Ready to test your knowledge?
Take a Electricity & Electronics - QMED Practice ExamOfficial Resources