Year 2024

Week # 2 Quiz 1

Q1. The regulation of an alternator is likely to be negative in case of

Q2. The mechanical power developed by a d.c. motor is maximum when the back e.m.f is

Q3. A DC shunt motor takes 5A at 100V when running light. Shunt field resistance is 50 ohm and armature resistance is 0.2 ohm. What will be driving power?

Q4. A 10-pole induction motor is supplied by a 6-pole alternator, which is driven at 1400 rpm. If the motor runs with a slip of 5%, what is its speed?

Q5. The desirable properties of transformer core material are

Q6. An alternator is supplying a load of 500 kW at a p.f of 0.5 lagging. If the power factor is raised to unity, how many more kW can alternator supply for the same kVA loading?

Q7. A 230V dc motor has an armature circuit resistance of 0.6 ohm. If the full load armature current is 30A and the no load armature current is 4A, the change in back emf from no load to full load will be

Q8. In a DC series motor, the torque developed is 20 Nm at 10 A load current, if the load current is doubled, the new torque will be

Q9. The frequency of the supply to the stator of an 8-pole induction motor is 50Hz and the rotor frequency is 3Hz. The slip is_________.

Q10. A 230/460 V transformer has a primary resistance of 0.2 ohm and reactance of 0.5 ohm and corresponding values for secondary are 0.75 ohm and 1.8 ohm respectively. Find secondary terminal voltage when supplying 10 A and 0.8 power factor lagging