is this done correctly?
A step-down transformer has 16000 turns on the primary and 95 turns on the secondary. If the rms emf across the secondary coil is 120 V, what is the maximum emf across the primary coil?
Np=16000 Ns=95 turns
Vs=120V Vp=?
Ns Vs
___ = ____
Np Vp
Ns*Vp=Vs*Np
Vp= Vs*Np
_____
Ns
= 120*16000
_________
95
= 20210.53 V
20,210 would indeed be the rms voltage
however it asked for the maximum voltage.
Multiply by sqrt 2
28582
Yes, the calculation is done correctly.
To solve this problem, you can use the turns ratio equation for transformers. The turns ratio equation states that the ratio of the number of turns in the primary coil (Np) to the number of turns in the secondary coil (Ns) is equal to the ratio of the voltage across the secondary coil (Vs) to the voltage across the primary coil (Vp).
In this case, you are given that Np is 16000 turns, Ns is 95 turns, and Vs is 120V. You need to find Vp, the maximum emf across the primary coil.
By rearranging the turns ratio equation, you can solve for Vp:
Vp = (Vs * Np) / Ns
Substituting the given values, you get:
Vp = (120V * 16000) / 95
Calculating this expression, you will get Vp = 20210.53V.
Therefore, the maximum emf across the primary coil is approximately 20210.53V.