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
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
46 comments Page 2 of 5.

Faisal said:   8 years ago
The Formula is this, R1=(N1/N2)^2 RL.
and R1 is given, N1 is given, N2 is given,
So, 250=(50/10)^2 RL.
250 = 25 RL.
Therefore, RL = 250 * 25 = 6250.
(2)

ROCKY said:   8 years ago
Transformation ratio is N2/N1. Am I right?
(1)

Arjun said:   9 years ago
Reflective resistance = {(1/k^2)*Rload}.

Sandeep Kumar said:   9 years ago
N2/N1= Sq.rt(R2/R1)
10/50 = Sq.Rt(250/R1)
(1/5)^2 = 250/R1.
R1=250*25 = 6250.
(1)

Vyankatesh badgujar said:   9 years ago
N1= 50 , N2 = 10.

Turn ratio K = N2/N1 = 10/50,
K = 1/5 = 0.2,
Now, R2/R1 = K^2.

R1 = R2/K^2,
= 250/0.2^2,
R1 = 6250 ohms.
(1)

Santosh murkut said:   9 years ago
The transformation ratio is said that N2/N1 = V2/V1 = I1/I2 = K.

Hence,

1) A resistance R1 in primary become K^2 * R1 when transferred to the secondary.

2) A resistance R2 in secondary become R2 / K^2 when transferred to the primary.

Therefore,

R1 = 250 / (10/50)^2 = 6250 ohm.

Rudra said:   1 decade ago
What will be the Phasor diagram for it?

Bhawana Singh said:   1 decade ago
Turn ratio will proportional to square of load then square of resistance in secondary upon primary 2n square.

Sandip chhatrola said:   1 decade ago
K^2 = R2/R1.

1/25 = 250/R1.

R1 = 6250 ohm.

Akash.bhure said:   1 decade ago
Solution:

No.of turns in the primary(N1) = 50.

No.of turns in the secondary(N2) = 10.

Turns ratio(K) = N2/N1 = 10/50 = 0.2.

Secondary load resistance(R2) = 250 Ohm.

Reflective resistance(R1) = R2/K^2.

(R1) = 250/(0.2)^2.
(R1) = 250/0.04 = 6250 ohm's.


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