A transformer for a distribution line receives 2V ac and step up to 240V ac. The secondary contains 300 turns and draws 10 A. Calculate; 1). The number of turns in the primary coil? 2). The current in the primary? 3). The power in the primary?

1 Answer
Jun 16, 2018

Please see the explanation below.

Explanation:

The equation for the trasformer is

#U_p/U_s=n_p/n_s#

The primary voltage is #U_p=2V~#

The secondary voltage is #U_s=240V~#

The number of turns of the secondary coil is #n_s=300 "turns"#

The number of turns of the primary is

#n_s=U_p/U_s*n_s=2/240*300=2.5 "turns"#

The power is

#P=U_pI_p=U_sI_s#

The current in the secondary is #I_s=10A#

The current in the primary is

#I_p=U_s/U_p*I_s=240/2*10=1200A#

The power in the primary is

#P_p=1200*2=2400W#