Question

20. A step-down transformer is used for a rechargeable phone.
    a. What is the voltage output of a transformer used for rechargeable flashlight batteries, if its primary

    has 400 turns, its secondary 2.5 turns, and the input voltage is 110 V?

    b. What input current is required to produce a 0.50 A output?

    c. What is the power input?

Answer 1

Given that Np = = 400 kurns Ns 2.5 buons Vp = 110v Youkput Vs = ? is given by Transformer Ratio Vs Vp 1) Ns Np Vs Ns x Up Np Vs = 8.5 X 110 400 Vs = 0.6875 v a9 Output Volkage of a kransformer. is 0.6875 by 67 Transformer ratio is given Vs Vp Ie Is Ns Np Given that Ýs = 0.50 A 15 x. Ig Ne

Ip ll 2.5 400 x 0.5 Tp = 0.003125 A Input Current is 0.003125 A o power loput PP Ip Vp = 0.00.3125 X 110 Pp = 0.34375 W