Question

A step-up transformer has 300 turns of primary winding and 450 turns of secondary winding. A primary is connected to 150 V and the current flowing through it is 9A. The current and voltage in the secondary are 

Options

• 13.5 A, 100 V

• 13.5 A, 225 V

• 4.5 A, 100 V

• 6.0 A, 225 V

Answer 1

6.0 A, 225 V

Explanation:

Given that, number of turns in primary winding, N_p = 300

Number of turns in secondary winding, N_s = 450

Primary voltage, V_p = 150 V

Primary current, I_p = 9 A

For step-up transformer,

`"V"_"S"/"V"_"P" = "N"_"S"/"N"_"P"`

`"V"_"S"/150 = 450/300`

`=> "V"_"S" = 450/300 xx 150`

`=> "V"_"S" = 225 "V"`

Again, V_pl_p =V_sl_s 

150 × 9 = 225 × I_s

`"I"_"s" = 1350/225` = 6.0 A