Electrical Engineering - Transformers - Discussion

Discussion Forum : Transformers - General Questions (Q.No. 11)
11.
How many primary volts must be applied to a transformer with a turns ratio of 0.1 to obtain a secondary voltage of 9 V?
9 V
90 V
900 V
0.9 V
Answer: Option
Explanation:

We know that, V2/V1 = N2/N1.

Given V2 = 9v, N2/N1 = 0.1

Therefore, 9v/V1 = 0.1

V1 = 9v/0.1 = 90v.

For more detail: Step Down Transformer - Circuit with Simulation.

Discussion:
24 comments Page 2 of 3.

Knowledge said:   1 decade ago
Don't try to memorize it as n1/n2 or n2/n1....It may cause trouble. Get your basics right.

SADDAM HUSSAIN said:   1 decade ago
Turn ratio is N1/N2= 0.1.

V2/V1 = N2/N1 = 10.

9/V1 = 10.
V1 = 9/10.
SO V1 = 0.9V.

Ravindra rawat said:   1 decade ago
We know that,

k = v2/v1 = n2/n1.

n2/n1 = 0.9.

v2 = 9v.

v1 = 9/0.9 = 90v answer.

Yogesh sabota said:   1 decade ago
I agree with farah this is incorrect
turn ratio=n1/n2=1/10
therefore
v1=0.9v

Farah said:   1 decade ago
But turn ratio Np/Ns=0.1

Then,

Vp/Vs=Np/Ns
Vp/9=0.1
Vp=9

Is it correct?

Adesh thakur said:   10 years ago
I am very confused what is the turn ratio & transformer ratio tell me.

Amani naidu said:   9 years ago
Turns ratio = n1/n2.
Transformation ratio = n2/n1 .
So answer is 0.9v.
(1)

Mei said:   8 years ago
Turns ratio and transformation ratio is different. Please check it.

Amol said:   9 years ago
You are right @Ram.

The hv winding turns are always more than lv.

Pokhor said:   5 years ago
If the turn ratio is less than 1, it is a step-down transformer.


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