[amp_mcq option1=”deflecting” option2=”controlling” option3=”damping” option4=”any of the above” correct=”option3″]
Electrical machine design
2. In D.C. machines the usual limit of slot pitch is
[amp_mcq option1=”between 5 to 10 mm” option2=”between 10 to 15 mm” option3=”machines the usual limit of slot pitch is A. between 5 to 10 mm B. between 10 to 15 mm C. between 15 to 20 mm” option4=”between 25 to 35 mm” correct=”option1″]
Detailed SolutionIn D.C. machines the usual limit of slot pitch is
3. In D.C. machines, ir order to prevent excessive distortion of field form by the armature reaction, the field mmf must be made
[amp_mcq option1=”equal to that of armature mmf” option2=”less in comparison with the armature mmf” option3=”machines, ir order to prevent excessive distortion of field form by the armature reaction, the field mmf must be made A. equal to that of armature mmf B. less in comparison with the armature mmf C. large in comparison with the armature mmf” option4=”none of the above” correct=”option3″]
4. In a single phase power factor meter the phase difference between the currents in the two pressure coils is
[amp_mcq option1=”exactly 0°” option2=”approximately 0°” option3=”exactly 90°” option4=”approximately 90°” correct=”option2″]
5. In a low power factor wattmeter the compensating coil is connected
[amp_mcq option1=”in series with current coil” option2=”in parallel with current coil” option3=”in series with pressure coil” option4=”in parallel with pressure coil” correct=”option1″]
Detailed SolutionIn a low power factor wattmeter the compensating coil is connected
6. Power transformers have rating
[amp_mcq option1=”equal to 50 kVA” option2=”equal to 100 kVA” option3=”above 200 kVA” option4=”none of the above” correct=”option3″]
7. The rectifier instrument is not free from
[amp_mcq option1=”temperature error” option2=”wave shape error” option3=”frequency error” option4=”all of the above” correct=”option4″]
8. The usual values of maximum flux densities for distribution transformers using hot rolled silicon steel are
[amp_mcq option1=”0.5 to 0.8 Wb/m2″ option2=”0.8 to 1.0 Wb/m2″ option3=”1.1 to 1.35 Wb/m2″ option4=”1.4 to 1.8 Wb/m2″ correct=”option2″]
9. In a dynamometer 3-phase power factor meter, the planes of the two moving coils are at
[amp_mcq option1=”0°” option2=”60°” option3=”90°” option4=”120°” correct=”option2″]
10. Which of the following instruments indicate the instantaneous value of the electrical quantity being measured at the time at which it is being measured ?
[amp_mcq option1=”Absolute instruments” option2=”Indicating instruments” option3=”Recording instruments” option4=”Integrating instruments” correct=”option2″]