Electrical Engineering - Transformers - Discussion

Discussion Forum : Transformers - General Questions (Q.No. 13)
13.
A certain transformer has a turns ratio of 1 and a 0.85 coefficient of coupling. When 2 V ac is applied to the primary, the secondary voltage is
1.7 V
0.85 V
1 V
0 V
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
22 comments Page 2 of 3.

Pmc said:   1 decade ago
Voltage induce in a transformer = (coeff. of coupling)*(ideal v).

Normally we take coefficient of coupling as 1.

But here it is mentioned as 0.85.
= 0.85*2.
= 1.7.

Saumya tripathi said:   1 decade ago
Please explain clearly relation among coefficient of coupling, voltage, turns ratio.

Subhransu said:   1 decade ago
According to transformation ratio E2/E1=N2/N1=K.
So E2/2=1=.85.
E2=2*.85=1.7V.

Pawan said:   1 decade ago
k = n2/n1 = v2/v1.
0.85 = 1 = v2/2.
v2 = 2*0.85.
v2 = 1.7.

Kiran said:   1 decade ago
No its 0.85 only. 85% of primary will link with secondary why?

ROOPESH D M said:   1 decade ago
We know that turns ratio = K = (N2/N1) = (V2/V1).

K = 1.
V1 = 2V.

Therefore V2 = V1*K = 2*1 = 2V.

But the coefficient of coupling is 0.85.

It indicates that only 85% of flux is linking to secondary, from primary.

So 2V*0.85 = 1.7 V.

Rahul hirave said:   10 years ago
Why transformer rating in kva not a kw?

Ram Krishna said:   10 years ago
There are two losses in transformer:

1. Core loss/iron loss-it is due to current and current is measured in ampere.

2. Winding/copper loss- it is due to voltage and unit of voltage is volt.

That means total loss-core-loss and copper loss.

So VA (volt ampere).

Kilo is introduced due to heavy current measured. That's a bigger unit. So, KVA.

Its clear, thanks.

Vignesh surya said:   9 years ago
v2 v1 = n2 n1.
v2/2 = 1 * 0.85.
v2 = 2 * 0.85.

Therefore v2 = 1.7.
(1)

Changaiz khan said:   7 years ago
Best explanation, thanks @Ram Krishna.


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