Number of turns in the primary coil and the secondary coil of an ideal transformer are 500 and 2500 respectively. If current in the secondary coil is 0.2 A, calculate current in the primary coil. Also calculate transformer ratio. If voltage in the secondary coil is 750 V, calculate voltage in the primary coil.

Options

A. 150 V
B. 160 V
C. 170 V
D. 140 V

Answer

A

Explanation

Here, `N_1` =500 , `N_2`= 2500
`I_1`=? , `I_2`= 0.2 A
`V_1`= ? , `V_2`= 750 V
Transformation ratio `r=N_2/N_1`
`=2500/500`
`therefore` r=5
For current in primary coil,
`N_1/N_2=I_2/I_1`
`therefore I_1=I_2 xx N_2/N_1`
= 0.2 x 5 =1.0 A
For voltage in primary coil,
`N_2/N_1=V_2/V_1`
`therefore V_1=V_2 xx N_1/N_2`
`= 750xx500/2500`
`therefore V_1`= 150 V