18. The primary coil of a step-up transformer is connected acrossthe terminals o
ID: 1671706 • Letter: 1
Question
18. The primary coil of a step-up transformer is connected acrossthe terminals of a standard wall socket, and resistor 1 with aresistance R1 is connected across the secondary coil.The current in the resistor is then measured. Next, resistor 2 witha resistance R2 is connected directly across theterminals of the wall socket (without the transformer). The currentin this resistor is also measured and found to be the same as thecurrent in resistor 1. How does the resistance R2compare to the resistance R1? The primary coil of a step-up transformer is connected acrossthe terminals of a standard wall socket, and resistor 1 with aresistance R1 is connected across the secondary coil.The current in the resistor is then measured. Next, resistor 2 witha resistance R2 is connected directly across theterminals of the wall socket (without the transformer). The currentin this resistor is also measured and found to be the same as thecurrent in resistor 1. How does the resistance R2compare to the resistance R1? 18. The primary coil of a step-up transformer is connected acrossthe terminals of a standard wall socket, and resistor 1 with aresistance R1 is connected across the secondary coil.The current in the resistor is then measured. Next, resistor 2 witha resistance R2 is connected directly across theterminals of the wall socket (without the transformer). The currentin this resistor is also measured and found to be the same as thecurrent in resistor 1. How does the resistance R2compare to the resistance R1?Explanation / Answer
We have Is = Vs / R1 Substitute this in Is = Ip ( Np / Ns) Vs / R1 = Ip ( Np / Ns) then substitute Vs in Vs = Vp Ns / Np Then finally u get Ip = ( 1 /R1 ) ( Ns / Np )2 Vp comparing this with Ip = Vp/ R2 then we have R2 = (Np / Ns)2R1 I hope this helps you.