[amp_mcq option1=”To improve cooling” option2=”To reduce copper losses” option3=”machines fractional pitch winding is used A. To improve cooling B. To reduce copper losses C. To increase the generated e.m.f.” option4=”To reduce the sparking” correct=”option3″]
The correct answer is: C. To increase the generated e.m.f.
Fractional pitch winding is a type of winding used in DC machines to increase the generated e.m.f. It is done by winding the coils at a fractional part of the pole pitch. This results in a longer path for the magnetic flux to travel, which in turn increases the induced e.m.f.
The other options are incorrect because:
- Option A is incorrect because fractional pitch winding does not improve cooling. In fact, it can make cooling more difficult because the coils are closer together.
- Option B is incorrect because fractional pitch winding does not reduce copper losses. In fact, it can increase copper losses because the coils are longer.
- Option D is incorrect because fractional pitch winding does not reduce sparking. In fact, it can make sparking more likely because the coils are closer together.
I hope this helps! Let me know if you have any other questions.