A commutator with a diameter of 50 cm rotating at ___

Electrical Engineering MCQ Electrical Machines MCQ
1

A commutator with a diameter of 50 cm rotating at 1000 rpm.

For a brush width of 1.5 cm, find the time of commutation in ms.

A. 0.443.
B. 0.573.
C. 0.512.
D. 0.649.

Show Answer

Answer: B

Share your understanding of this question with the correct explanation.

2

The time of commutation can be calculated using the formula:

Time of commutation = (Brush width * 60) / (π * Commutator diameter * RPM)

Given:
Brush width = 1.5 cm
Commutator diameter = 50 cm
RPM = 1000

Substituting these values into the formula:

Time of commutation = (1.5 * 60) / (π * 50 * 1000)
Time of commutation = 90 / (π * 50000)
Time of commutation ≈ 0.573 milliseconds

Therefore, the time of commutation is approximately 0.573 milliseconds. The correct answer is B.