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 3 of 5.
Arun Kumar Raju C said:
1 decade ago
Ns/Np = sqrt(load resistance/source resistance).
Eshan Mishra said:
1 decade ago
There is difference b/w the terms if simply turn ratio, voltage ratio is mention and transformation ratio is mention in the question.
Eg:- transformation ratio is k, k=[V2/V1=N2/N1=I1/I2].
Simple turn ratio, voltage ratio is equal to 1/k
N1/N2, V1/V2.
And there is one more important relation,
(V2/V1)=Square root(R2/R1).
Eg:- transformation ratio is k, k=[V2/V1=N2/N1=I1/I2].
Simple turn ratio, voltage ratio is equal to 1/k
N1/N2, V1/V2.
And there is one more important relation,
(V2/V1)=Square root(R2/R1).
Engr. Mamoona Akbar said:
1 decade ago
t2/t1 = sqrt (load impedance/source impedance).
10/50 = sqrt (250/x).
0.2*0.2 = 250/x.
x = 250/0.04.
x = 6250.
10/50 = sqrt (250/x).
0.2*0.2 = 250/x.
x = 250/0.04.
x = 6250.
Ododo said:
1 decade ago
Please am confused, turns ratio is it the same as transformer ratio?
I saw that turns ratio = N2/N1, and I still saw that turns ratio = N1/N2, which one is correct with proofs please.
I saw that turns ratio = N2/N1, and I still saw that turns ratio = N1/N2, which one is correct with proofs please.
Yatish Ahire said:
1 decade ago
Primary resistance R1 = R2/(K)2.
Here,
K = N2/N1 = 10/50 = 0.2.
Hence,
R' = 250/0.2*0.2 = 6250 Ohm.
Here,
K = N2/N1 = 10/50 = 0.2.
Hence,
R' = 250/0.2*0.2 = 6250 Ohm.
Mallikarjun said:
1 decade ago
R2' = r2/(kxk).
r2 = 250 ohms.
k = n2/n1 = 0.2.
(kXk) = 0.04.
R2' = 250/0.04 = 6250.
r2 = 250 ohms.
k = n2/n1 = 0.2.
(kXk) = 0.04.
R2' = 250/0.04 = 6250.
S.ANJINEYULU NAIK said:
1 decade ago
Turn ratio, k=N2/N1.
=10/50.
=1/5=0.2.
Actual resistance in secondary circuit is R2=250 ohm's.
Reflective resistance means, the secondary resistance referred to primary winding is,
R2'=R2/k^2.
=250/ (0.2) ^2.
=250/0.04.
=6250 ohm's.
=10/50.
=1/5=0.2.
Actual resistance in secondary circuit is R2=250 ohm's.
Reflective resistance means, the secondary resistance referred to primary winding is,
R2'=R2/k^2.
=250/ (0.2) ^2.
=250/0.04.
=6250 ohm's.
Akshat gupta said:
1 decade ago
Where
n1=50
n2=10
r2=250ohm
so
resistance matching r1= (n1/n2)^*rl
hence,
r1=(50/10)^2*250
=25*250
=6250 ohm
n1=50
n2=10
r2=250ohm
so
resistance matching r1= (n1/n2)^*rl
hence,
r1=(50/10)^2*250
=25*250
=6250 ohm
Virendra ranpise said:
1 decade ago
Resistance ratio=R2/R1
Xmer ratio(K)=N2/N1
Where,
R1=Primary winding resistance
R2=secondary winding resistance
N1=Primari winding turns
N2=secondary winding turns
FORMULA FOR CALCULATING R1
R2/R1 = K square
i.e. R2/R1 = (N2/N1)square
250/R1 = (10/50) square
So
R1 = (250) / ((10/50) square)
R2=6250 ohm
Xmer ratio(K)=N2/N1
Where,
R1=Primary winding resistance
R2=secondary winding resistance
N1=Primari winding turns
N2=secondary winding turns
FORMULA FOR CALCULATING R1
R2/R1 = K square
i.e. R2/R1 = (N2/N1)square
250/R1 = (10/50) square
So
R1 = (250) / ((10/50) square)
R2=6250 ohm
Nidhi M J said:
1 decade ago
Copper losses produced by r2 in primary side must be same as that in secondary side.
I1^2*r2'=I2^2*r2
R2'= (I2/I1) ^2*r2
Where I2/I1=N1/N2.
I1^2*r2'=I2^2*r2
R2'= (I2/I1) ^2*r2
Where I2/I1=N1/N2.
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