Q.17- Write the construction and working principle of single phase transformer. Q.18- Derive the EMF equation of a single phase transformer. Q.19- Differentiate between the core type and shell type transformer. Q.20- Draw the phasor diagram of a single phase practical transformer at RL load. Q.21- Explain the losses in transformer. Q.22- A 250 KVA, 11000/415 V, 50 HZ, single phase transformer has 80 turns on the secondary side, calculate: (i) The approximate value of full load primary and secondary currents. (ii) The approximate number of primary turns. (iii) The maximum value of the flux.