Question

When Copper brushes are used in DC machine?

a.

Where low voltage and high currents are involved

b.

Where high voltage and small currents are involved

c.

Cannot be determined

d.

Where low voltage and low currents are involved

Posted under DC Machines

Answer: (a).Where low voltage and high currents are involved

Interact with the Community - Share Your Thoughts

Uncertain About the Answer? Seek Clarification Here.

Understand the Explanation? Include it Here.

Q. When Copper brushes are used in DC machine?

Similar Questions

Explore Relevant Multiple Choice Questions (MCQs)

Q. In DC generators, current is fed up to the external circuit from armature through _______

Q. What are the number of the brushes in the wave winding?

Q. Which conductors are in point of contact with brushes?

Q. In case of DC machine winding, number of commutator segments is equal to ______

Q. How total number of brushes in a commutator are determined in a given DC machine?

Q. In a DC generator the ripples in the direct emf generated can be reduced by________

Q. The drop in the voltage for which of the following types of brush can be expected to be least?

Q. What is the requirement of the good commutation?

Q. How to avoid grooves in the commutation of DC machine with the help of brush?

Q. Reason behind the rapid wear of brushes is __________

Q. For both lap and wave windings, what is the number of commutator bars equal to?

Q. Spacing between the brushes for a 4-pole machine in terms of commutator segments for 12 conductor segments is _____

Q. Spacing between the brushes for a 4-pole machine in terms of commutator segments is equal to 6. What will be the number of armature slots?

Q. What is the range of the brush friction coefficients for medium category?

Q. Specific resistance for a brush is given by _________

Q. How many poles to be used in DC machine if brushes are placed 4 commutator segments apart for 16 commutator segments?

Q. DC generators are disconnected/connected from/to the busbars only under the floating condition because ____________

Q. In PMDC motors we use magnetic material with ___________

Q. In PMDC magnetic material is placed instead of _____________

Q. PMDC motors are _________________

Recommended Subjects

Are you eager to expand your knowledge beyond DC Machines? We've handpicked a range of related categories that you might find intriguing.

Click on the categories below to discover a wealth of MCQs and enrich your understanding of various subjects. Happy exploring!