A step-up transformer has 26 turns on the primary coil and 720 turns on the secondary coil. If this transformer is to produce an output of 4100 V with a 16-mA current, what input current and voltage are needed?
<h2>Answer:</h2>The input current and voltage needed are 443 mA and 148 V respectively.
<h2>Explanation:</h2>In a step-up transformer, the relationship between the number of turns in its primary coil (), the number of turns in its secondary coil (
), the input voltage (
), the output voltage (
), the input current (
), and the output current (
) is given by;
=
=
This implies that;
=
---------------------(i)
=
---------------------(ii)
From the question;
= 26 turns
= 720 turns
= 4100V
= 16mA = 16 x 10⁻³A
(a) Substitute these values into equation (ii) as follows;
=
Solve for ;
= 720 x 16 x 10⁻³ / 26
= 443 x 10⁻³
= 443 mA
Therefore the input current needed is 443mA
(b) Also, substitute those values into equation (i) as follows;
=
Solve for ;
= 4100 x 26 / 720
= 148 V
Therefore, the input current needed is 148 V
