Question

The primary coil of an ideal step-up transformer has 100 turns and the transformation ratio is also 100. The input voltage and power are 220 V and 1100 W, respectively. Calculate the 

(a) number of turns in secondary
(b) current in the primary
(c) a voltage across secondary
(d) current in secondary
(e) power in secondary

Answer 1

(a) Number of turns in secondary coil is given by 

`N_S/N_P=n`

`=>N_S/100=100`

⇒N_S=10,000

(b) Current in primary is given by

I_PV_P=P

`=>I_P=1100/220=5A`

(c) Voltage across secondary is given by 

`V_S/V_P=N_S/N_P=n`

⇒V_S=100×220=22,000 V

(d) Current in secondary is given by

V_SI_S=P

`=>I_S=P/V_S=1100/22000=0.05A`

(e) Power in secondary is power in primary in an ideal transformer.

= 1,100 W