Year 2024

Week # 2 Quiz 2

Q1. A 40 KVA transformer has iron loss of 450 watt and full load copper loss of 850 watt. If the power factor of the load is 0.8 is lagging. The full load efficiency of the transformer in % is

Q2. A transformer can have zero regulation at

Q3. A three phase synchronous motor can be braked electrically by

Q4. A 50 kVA, 4400/220 V transformer has primary winding and secondary winding resistance are R1 = 3.45 \(\Omega\) and R2 = 0.009 \(\Omega\) respectively. Calculate the equivalent resistance of the transformer as referred to primary side.

Q5. A single phase transformer has 400 turns in the primary winding and 1500 turns in the secondary winding. If the primary winding is connected to a 50 Hz supply at 500 V, calculate the voltage induced in the secondary.

Q6. The speed of 4 pole, 60 Hz synchronous machine will be

Q7. Following parameter(s) may affect the performance of a motor

Q8. A synchronous motor, fed from infinite bus , is working at half load, if increased in it's field current causes a reduction in the armature current, then the motor is

Q9. A star connected synchronous generator rated at 500 MVA, 50 kV has a reactance of 0.5 pu. Find the ohmic value of the reactance.

Q10. Hunting of a synchronous motor may be due to