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 4 of 5.
Sanjeev Kr. Rajoria said:
1 decade ago
Transformation ratio a = N1/N2
so
a=50/10=5
now
load resistance referred to primary= (a^2)*(load resistance)
so
the reflected load = 5^2*250
= 25*250
= 6250 ohm
So the correct ans is (c)= 6250 ohm
so
a=50/10=5
now
load resistance referred to primary= (a^2)*(load resistance)
so
the reflected load = 5^2*250
= 25*250
= 6250 ohm
So the correct ans is (c)= 6250 ohm
Kuldeep Bisht said:
1 decade ago
Primary resistence R'=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
Amit Ranjan said:
1 decade ago
Eqv.resistance referred to primary=r1+r2/(k*k)
Here r1 is not given
k=10/50=1/5
Hence ans = 250/(1/25) = 6250 ohm.
Here r1 is not given
k=10/50=1/5
Hence ans = 250/(1/25) = 6250 ohm.
Sunil gorga said:
1 decade ago
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
r1=250*5=6250
v1*v1/r1=v2*v2/r2
(v1/v2)^2=r1/r2
we know n1/n2=v1/v2
so (50/10)^2=r1/250
r1=250*5=6250
Anil said:
1 decade ago
Resistance matching R1=(n1/n2)^2*rL
hence, r1=(50/10)^2*250
= 25*250
=6250 ohm
hence, r1=(50/10)^2*250
= 25*250
=6250 ohm
Bhagyashree said:
1 decade ago
R2=250
k=n1/n2=50/10
R1=R2*k^2
=250*(2500/100)
R1=6250ohm
k=n1/n2=50/10
R1=R2*k^2
=250*(2500/100)
R1=6250ohm
Mahendra dhakchavle said:
1 decade ago
R2=250
k=n1/n2=50/10
R1=R2*k^2
=250*(2500/100)
R1=6250ohm
k=n1/n2=50/10
R1=R2*k^2
=250*(2500/100)
R1=6250ohm
Kalyan said:
1 decade ago
Rs=250
I1^2Rs=I2^2Rf
(I1/I2)^2*Rs=Rf
From Transformation ratio N2/N1=I1/I2=K
(50/10)^2*250=Rf
25*250=Rf
Rf=6250ohm
I1^2Rs=I2^2Rf
(I1/I2)^2*Rs=Rf
From Transformation ratio N2/N1=I1/I2=K
(50/10)^2*250=Rf
25*250=Rf
Rf=6250ohm
Sunil keshari said:
1 decade ago
N1=50
N2=10
R2=250 ohm
K=(N2/N1)
(R2/R1)=K^2
(250/R1)=(10/50)^2
R1=(2500*250)/100
R1=6250 ohm
N2=10
R2=250 ohm
K=(N2/N1)
(R2/R1)=K^2
(250/R1)=(10/50)^2
R1=(2500*250)/100
R1=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.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers