Question

Directions: It consists of two statements, one labelled as the ‘Statement (I)’ and the other as ‘Statement (II). Examine these two statements carefully and select the answer using the codes given below:

Statement (I): The ‘Rating’ of alternators is determined by their heating and hence, the losses in them.

Statement (II): Along with the voltage, frequency and MVA the operating minimum lagging power factor has also to be included in the Rating specifications.

1. Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
2. Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)
3. Statement (I) is true but Statement (II) is false
4.

Statement (I) is false but Statement (II) is true

Answer 1

Correct Answer - Option 1 : Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

Rating of Alternator:

• The rating of an alternator is determined by the maximum temperature rise during its operation.
• The temperature rise or heating of alternator depends upon the cumulative effect of copper losses and core losses.
• Some of the losses depend on the voltage and some of the losses depend on the current and hence rating of the machine depends on losses occurring in them.
• Therefore, along with the voltage, frequency, and MVA the operating minimum lagging power factor has also to be included in the Rating specifications.

 

Therefore, ​both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I).