A step-up transformer has 40 turns on its primary and 100 turns on its secondary. When the primary is supplied with an alternating current at 140 V, what is the voltage across the secondary?
what is 140*100/40 ?
To find the voltage across the secondary of a step-up transformer, you can use the turns ratio formula.
The turns ratio formula is given by:
Turns ratio = Ns/Np
Where:
Ns is the number of turns on the secondary coil
Np is the number of turns on the primary coil
In this case, the primary coil has 40 turns (Np = 40) and the secondary coil has 100 turns (Ns = 100).
Using the turns ratio formula, we can calculate the turns ratio:
Turns ratio = Ns/Np = 100/40 = 2.5
The turns ratio tells us that for every 2.5 turns on the primary coil, we have 1 turn on the secondary coil.
Now, to find the voltage across the secondary coil, we can use the voltage ratio formula:
Voltage ratio = Vs/Vp
Where:
Vs is the voltage across the secondary coil
Vp is the voltage across the primary coil
Since the primary coil is supplied with an alternating current at 140 V (Vp = 140 V), we can substitute this value into the voltage ratio formula:
Voltage ratio = Vs/140 = 2.5
Solving for Vs:
Vs = 2.5 * 140
Vs = 350 V
Therefore, the voltage across the secondary of the step-up transformer is 350 V.