Electrical Engineering - Transformers - Discussion
Discussion Forum : Transformers - General Questions (Q.No. 4)
4.
If a transformer has 50 turns in the primary winding and 10 turns in the secondary winding, what is the reflective resistance if the secondary load resistance is 250 
?
?250
25
6,250
62,500
Discussion:
46 comments Page 5 of 5.
Abhishek mohapatra said:
8 years ago
From the basics:
You have to find what resistance on primary will have similar effect as 250 on secondary.
in ideal transformer power associated with primary equals secondary hence V2^2/250 = v1^2/Rreq. similarly V2*I2 =V1*I1. if you know what voltages are related in the same way as a number of turns i.e V2/V1 = N2/N1 then you can easily relate all currents and impedances.
You have to find what resistance on primary will have similar effect as 250 on secondary.
in ideal transformer power associated with primary equals secondary hence V2^2/250 = v1^2/Rreq. similarly V2*I2 =V1*I1. if you know what voltages are related in the same way as a number of turns i.e V2/V1 = N2/N1 then you can easily relate all currents and impedances.
Vaibhav said:
7 years ago
Can I find reflected impedance or turns ratio if the only efficiency of the transformer is provided?
(1)
Majid Mahmood said:
6 years ago
According to my calaculation:
v1i1 = v2i2
v1*v1/r1 = v2*v2/r2
(v1/v2)^2 = r1/r2.
We know n1/n2 = v1/v2
so (50/10)^2 = r1/250 => 25 = r1/250,
r1 = 250 * 25 = 6250.
v1i1 = v2i2
v1*v1/r1 = v2*v2/r2
(v1/v2)^2 = r1/r2.
We know n1/n2 = v1/v2
so (50/10)^2 = r1/250 => 25 = r1/250,
r1 = 250 * 25 = 6250.
(12)
Richa said:
5 years ago
Transformation ratio is N1 (Primary)/N2 (secondary).
Suresh said:
4 years ago
Voltage of secondary 200v, transformer ration N1:N2= 200:100, X=12 Ohms and Rl = 4 Ohms.
Estimate the RMS value of the primary current I1 and Secondary Current I2 and Estimate the power in watts.
Estimate the RMS value of the primary current I1 and Secondary Current I2 and Estimate the power in watts.
HRD said:
2 years ago
R1 = (N1/N2)^2 * RL,
R1 = (50/10)^2 * 250,
R1 = 6250.
R1 = (50/10)^2 * 250,
R1 = 6250.
(6)
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