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The turns ratio required to match 80Discussion page for Q.439 electrical engineering questions and answers (3)Source to a 320Discussion page for Q.439 electrical engineering questions and answers (4)burden is

[A]. 80
[B]. 20
[C]. 4
[D]. 2



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Jeykishan Kumar.ksaid:(December 14, 2010)
The turns ratio is proportional to the square root of the load.
Jensaid:(January 19, 2011)
Turns Ratio2 = Load Impedance/Source Impedance


Anirudhyasaid:(January 21, 2011)
v1 I1=v2 I2
sq of (v1/v2)=r2/r1
sq of (1/k)=r2/r1=4
1/k=2------this is the transmission ratio
k=1/2-----this is the transmission ratio
bcoz--n2/n1==transformation ratio
n1/n2==gear ratio
Vinay Kumarsaid:(January 25, 2011)
The turns ratio is proportional to the square root of the load.
Jegansaid:(March 9, 2011)
sq of (v1/v2)=r1/r2
Rajneeshsaid:(March 21, 2011)
Gear ratio=(n2/n1)^1/2
Pruthibiraj Goudasaid:(May 11, 2011)
Here r1=80 ohms, r2=320 ohms
we know v2/v1=i1/i2
=> k=(v1/v2)*(r2/r1)
=> k=1/k*(320/80)
Lookssaid:(May 30, 2011)

Turns ratio = sq rt (n2/n1) = 2

TMeswarsaid:(7. June 2011)
I want the frequency to be constant for the transformers?
Saminathansaid:(18. June 2011)
2T = load/source
2T = 320/80
T = 4/2
Azagusaid:(7. August 2011)
Here frequency can not be changed. Otherwise it is only transmitted.
In transformers we use the 50Hz because they operate at the same frequency due to the given load so we use the constant.
If the above statement is true that the turns ratio is equal to load/source then the answer comes 2.
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Someone said that the turns ratio is equal to the square of the load. Is it correct or not?
Enjoysaid:(6. November 2011)
gear ratio=a(n2/n1a)
Also R2=a^2*R1
Soujanyasaid:(13. November 2011)
What Kallan said is correct and less time consuming as well as easy to remember.
Satyasaid:(December 15, 2011)
As with a transformer, input power = output power i.e. energy is transformed, v1^2 / z1 = v2^2 /z2. therefore turns ratio = sqrt(z2/z1)
BHABANI SHANKAR BEHERAsaid:(January 12, 2012)
I am satisfied with Pruthiwi Raj's reply.
Shajeersaid:(January 16, 2012)
turns ratio = sqrt.(r2/r1)
= square meter (320/80)
= square (4)
= 2
seedsaid:(February 21, 2012)
also k=2
Dr. mofizsaid:(9. April 2012)
Why the transformer power in kva?
Nareshsaid:(11. April 2012)
Is this process applicable to all turns ratio problems?
Shivasaid:(25. April 2012)
The transformer power is given in kVA because the Cu loss only depends on voltage and current and is independent of the power factor.
Palivela Varaprasadsaid:(29. April 2012)
Therefore turns ratio n2/n1=root(4)=2
Dillip Kumar Dehurysaid:(6. May 2012)
Is there a technique to know the KVA rating of the transformer without a nameplate?
Dillip Kumar Dehurysaid:(6. May 2012)
Why is iron loss neglected in the cu.loss test?
Sirisaid:(May 23, 2012)
Cu losses do not depend on voltage, iron losses depend on voltage and Cu losses depend on current, also the power factor of t/f depends on the load and is therefore given in kva, while the power factor for motors is only depends on the design and is therefore given in kW.
Navdeep Sainisaid:(May 29, 2012)
The force is constant on both sides
Turns Ratio = I1/I2 = Square Root (R2/R1) = 2
Venkatesh Ssaid:(1. June 2012)
In question we understood that we convert the 320 ohms resistance in the secondary to 80 ohms in the primary (i.e. source) side. r'2 is 80, r2 is 320. Turns ratio is K.

r'2= (r2/K^2).
So k = square of (320/80).

Keerthisaid:(July 26, 2012)
The turns ratio is always proportional to the square root of the load.
onesaid:(5. September 2012)
The turns ratio is directly proportional to the square root of the load impedance to the source impedance, i.e. H. here is the square root of 320/80 = 2.
Anil kumarsaid:(20.10.2012)
As we know, V2/V1 = N2/N1 = I1/I2 = k.
Also V2/V1 = (V1/R1)*(R2/V2) = k.
=> (V2/V1)2 = R2/R1 = k.

Therefore turns ratio (k) = square root of (R2/R1)
= square root of (320/80)
= 2.

ASHOK WATHsaid:(December 23, 2012)
Ajit Kumarsaid:(February 1, 2013)
Why can't the transformer work on direct current?
Dr. G. Suresh Babusaid:(February 18, 2013)
Transformer works on the principle of Faraday's laws of electromagnetic induction; with mutual induction concept.

According to Ohm's law; Current I = V/Z.
V = supply voltage - back EMF.

Impedance Z =R+jX.
Reactance X =2 Pi f L.

We know that in the case of a DC supply, the frequency f is zero; no induced EMF, since there is no flux change at DC (Induced EMF e= N dq/dt;).

Current I =(supply voltage-back EMF)/R=j+ X.

Here the numerator increases (back EMF is zero) and the denominator decreases (since X = 0 and R is very small); consequently, I rises to a dangerous level, leading to burning of the windings if not properly fused.

Therefore, the DC supply should not be connected to the transformer; If connected, a mechanism for frequent switching on and off (such as SCR) should be provided.

Gopinadh Puvvadasaid:(February 18, 2013)
Assuming the transformer is ideal as losses in primary and secondary are equal.





So the answer is 2.

PABANsaid:(21st March 2013)
In the ideal transformer we know v2/v1 = i1/i2 = k.

v2/v1 = (v1/r1)*(r2/v2).

(v2/v1)^2 = r2/r1.

After calculation, the result is 2.

Utagsaid:(3. June 2013)
What is a converter transformer?
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Abhijitsaid:(22. August 2013)
What is the transformer turns ratio required for a 160 ohm load?
Pradip Pawarsaid:(25.09.2013)
Turns Ratio = Square Root of Load Impedance at Source Impedance.
Donfilasaid:(20. November 2013)
Copper losses are current square resistance losses. Or winding losses. {I*I*R}.
Sarahsaid:(30. November 2013)
Impedance or resistance both primary and secondary must be the same which implies Z01 = Z02.

Where Z01 = Z1+(Z2/k^2).
Z02 = Z2+(Z1*k^2).

Solving the above equations I got '1' which is not the answer.

Is it the right approach?

Engr. Mamoona Akbarsaid:(January 17, 2014)
Turns Ratio*2 = Load Impedance/Source Impedance.
Ranjeet Singhsaid:(January 21, 2014)
v2/v1 = i1/i2.

= v1/r1*r2/v2.

(v2/v1)^2 = r2/r1.

(k)^2 = r2/r1.

k^2 = 320/80.

k^2 = 4 .

k = 2.

coppersaid:(January 25, 2014)
Transformer power is KVA as iron and Cu losses only depend on voltage and current. Then it doesn't depend on the pf, so it just calls kva.
Gursewak Singhsaid:(March 2, 2014)
turns ratio = sqrt(r2/r1).
= Square (320/80).
= Square (4).
= 2.
Prakaschsaid:(March 9, 2014)
What is the turns ratio? please explain.
Arun Kumar Raju Csaid:(4. April 2014)
The turns ratio of a transformer is defined as the number of turns on its secondary divided by the number of turns on its primary.
Akash.bhuresaid:(30. April 2014)
Source Resistance (R1) = 80 ohms.

Lastwiderstand (R2) = 320 Ohm.

R1 = R2/K^2.
80 = 320/K^2.
K^2 = 320/80 = 4.
K = quadrat(4) = 2.

Saranyasaid:(May 18, 2014)
Single Phase Transformer 50Hz 200kVA 11kV/230V Test Results: No Load Test: Input = 1600 watts Short Circuit Test: 2600 watts Calculate All Day Efficiency Duty Cycle 160 kW 0.8 PF 8 hrs 100 kW unit PF 6 hrs remaining hrs no load .
Krishna Kantsaid:(May 29, 2014)
Numerical solution of single and three phase transformers.
Krishnasaid:(May 30, 2014)
What is the relationship between the number of turns and the resistance?
Prudhi Rajsaid:(28. June 2014)
The source side is assumed to be primary, then r1=80, and we must match the secondary (load) side since it is 320, i.e. r1'=320.

In fact, we know that whenever primary is referred to secondary,

So here,

ksquare*r1 = 320, which means that

kQuadrat = 320/r1=320/80=4.

i.e. k² = 4 then k=2.

Here k = transformation ratio.

Rpnagarajsaid:(1. August 2014)
The impedance is the square of the turns ratio.
What is MOG protection in transformer?
Sharjeelsaid:(1. November 2014)
(turns ratio)*2 = load impedance/source impedance.
Tagsaid:(17. November 2014)
Square root of load impedance/source impedance.

Then the answer is 4.

Ramakrishna18893said:(December 1, 2014)
The source belongs to the primary winding while the load belongs to the secondary winding. So to match or transfer the impedance from the primary to the secondary, k^2 (turns ratio) should be multiplied by the primary impedance, then it is set equal to the secondary impedance (matching is to achieve maximum power transfer). This is as pictured.

80*k^2 = 320.
k^2 = 4.
k = 2.

When going from secondary to primary, the secondary impedance must be multiplied by 1/k^2. Match it to the primary impedance to match. The same result is obtained.

sadsaid:(December 6, 2014)
what is resistance please reply
KALIDHASsaid:(January 1, 2015)
What things/parameters are required for sizing distribution transformers?
ashsaid:(January 14, 2015)
What is the actual formula for turns ratio, is it K=N1/N2 OR K=N2/N1 and what is the gear ratio?
Rajesh Khannasaid:(31 January 2015)
What does imbalance mean?
Sahebsaid:(February 11, 2015)
R(hv) = K^2*R(lv).

[v2/v1 = k,i2*r2/i1*r1 = k, R(hv)/R(lv) = k^2; k = 2; r2/r1 = k^2].

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Krishnakumarsaid:(3. June 2015)
During the current loss test (short circuit) we applied the rated current of the transformer. The transformer reaches its rated current at a certain voltage. It's a very small current loss that depends only on the voltage. So it's negligible.
Rangaswamy M.Dsaid:(July 13, 2015)
v2/v1 = i1/i2.
= v1/r1*r2/v2.
(v2/v1)^2 = r2/r1.

(k)^2 = r2/r1.
k^2 = 320/80.
k^2 = 4 .
k = 2.

Dudesaid:(4. August 2015)
N(s)/N(p) = E(S)/E(p)-1.

I(p) N(p) = I(s) N(p).

E(P)N(P) / R(P) = E(S)N(S)/R(S)-2.

From 1 and 2.

Sq (N(S)/N(P)) = R(s)/R(p).

I am not satisfied with this answer.

Turns ratio = E1/E2 = V1/V2 = N1/N2 = 1/k.

GAUTAMsaid:(January 18, 2016)
Clearly questioned:

Primary or source resistance R1 = 80 Ohm.

Secondary resistance R2 = 320.

We know that:

Transmission ratio k = N1/N2 = V1/V2 = R2/R1 = I2/I1.

SO K=320/80=4 is the correct answer.

Chandra Shekarsaid:(February 26, 2016)
320 = n^2*80.

n^2 = 320/80 = 4.

n = 2.

Hanumantha HKsaid:(March 5, 2016)
Especially guys discussed ok but there is a bug in there!

Gear ratio (n) = N1/N2 = V1/V2 = I2/I1.
The same transformer ratio is (K) = 1/n.

Bedeutet V2/V1 = N2/N1 = I1/I2 = K.

The question is turns ratio?
(v1)^2/R1= (V2)^2/R2.
Also (V1/V2)^2=R1/R2.

Gear ratio n = (N1/N2)^2=R1/R2=80/320=1/4.

If we do sqrt it will come =1/2.

What do you think of the above solution?

Amjad Moawiasaid:(1. May 2016)
Nein! @Hanumantha Hk.

The correct law is: vs/sp = NS/NP = IP/IS.

Please revise again.

Sudhasaid:(5. June 2016)
Can anyone solve this problem in a simple way?
Nestsaid:(July 20, 2016)
Sqr(Np/Ns) = Zp/Zs,

Because the turns ratio is Np/Ns, not Ns/Np.

Is there a technique to know the KVA rating of the transformer without a nameplate?
Hajj Bilalsaid:(10. November 2016)
Hallo, @Yash.

It should be necessary to measure the current and voltage of the transformer from the secondary. Then you can know the KVA rating of the transformer!

K. Gopal Krishnasaid:(December 13, 2016)
Here is the value in ohms.
d.h. resistiv
There will be more in winding.
n2/n1 = k,
320/80 = k,
= 4.
K.Gopalakrishnasaid:(December 13, 2016)
Gear ratio k = n2/n1.
Here the specified value is in ohms, so resistive.
That will be more in the winding.
d.h. 320/8 = 4.
Prafullasaid:(March 29, 2017)
When the primary resistance is transferred to the secondary winding. Then,
R2=K^2 R1.
320=K^2 80,
K^2=320/80 = 4.
K= √4 = 2.
MB Sharonsaid:(28. June 2017)
The National Instructional Media Institute (NIMI) book for industrial training.

Np=number of turns in the primary winding.
Ns=number of turns in the secondary side.
Zp=primary impedance or (source).
Zs = secondary impedance or (load).
Floor; Which Z = 80 Ohm.
Last Z = 320 Ohm.
Turns Ratio = 1:2 Answer = 2.
The 1:2 turns ratio matches the 80 ohm source impedance to a 320 ohm load.

Surinder Rajputsaid:(July 5, 2017)
Here is the little formula for impedance VS turns.
a= turns ratio, (Np/Ns)=square root of (Zp/Zs),
square root of (380/20)=4/1,
square root of (4/1)=2,
Also 2.
hemantsaid:(17. August 2017)
Can anyone provide a formula derivation to show turns ratio in terms of resistance?
Given that

R1 = 80 Ohm
R2 = 320 Ohm
transformer ratio,
K = N1/N2 = V1/V2=R2/R1=I2/I1.
= 320/80=4.

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Harschasaid:(25. November 2017)
If √(n2/n1) is the turns ratio, then what is n2/n1?
Mallikarjun Bhiradesaid:(December 10, 2017)
Explanation:- Given data, R1=80 ohms, R2=320 ohms, we have, R2/R1=K^2
Where K = transformation ratio

Life, K^2=320/80=4 => K=√(4)=2
But turns ratio = 1/K, now turns ratio = 1/2 = only 0.5!

Jh71 pasaid:(January 29, 2018)
Is it 2:1 or 1:2? Please tell me clearly.
B Shirishasaid:(January 30, 2018)
load impedance ÷ source impedance.
Ramesh Vankudothusaid:(July 2, 2018)
K2: R2%R1
K2: 320 %80
K = √4 => also 2.
Zoodeesaid:(6. Oct. 2018)
It should be 1/2.
Rakishsaid:(March 6, 2019)
Turns Ratio = √(R2/R1).
= √(360/80),
= √4,
= 2.
Jamessaid:(March 13, 2019)
Thanks everyone for explaining.
Adarsh ​​P Ksaid:(23.12.2019)
Gear Ratio = Square Root (Zs/Zp).
Sanchayan Singh Roysaid:(13.06.2020)
The impedance of the secondary side is Zs and that of the primary side is Zp.

So the formula is Zs = Zp* (N1/N2)^2.
now here we can say square root (Zs/Zp)= N1/N2.
Hence N1/N2= √(320/80).
And turns ratio = 2.

Hamayat Allahsaid:(25.12.2020)
Transmission ratio,n = NP/NS.
Khanindra Kalitasaid:(31. May 2021)
Source at 320 ohms, average primary side resistance is 320 and secondary side resistance is 80 ohms.

Now ,
We know that,

R1 = R2 * (N1/N2)^2,
320 = 80 * (N1/N2)^2,
(N1/N2)^2 = 320/80 = 4,
N1/N2 = √4.
= 2.

V1 * I1 = V2 * I2.
v1 * V1/R1 = V2 * V2/R2,
V1^2/R1 = V2^2/R2,
V1^2 / V2^2 = R1/ R2,
V1/V2 = √(R1/R2),
N1/N2 = √(80/320),
N1/N2 = 1/2 (turns ratio).

So the answer should be 1/2.

Hrithik'ssaid:(July 20, 2022)
v1*i1 = v2*i2.

V1^2/R1 = V2^2/R2.

V2^2 / V1^2 = R2/R1.
(k)^2 = r2/r1.
k^2 = 320/80.
k^2 = 4 .
k = 2.

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