Electrical Engineering - Transformers - Discussion

Discussion :: Transformers - General Questions (Q.No.3)

3. 

When the turns ratio of a transformer is 20 and the primary ac voltage is 12 V, the secondary voltage is

[A]. 12 V
[B]. 120 V
[C]. 240 V
[D]. 2,400 V

Answer: Option C

Explanation:

No answer description available for this question.

Ashar said: (Dec 4, 2010)  
n1/n2= 1/20=vi/v2
20*12=240

Nitesh said: (Dec 20, 2010)  
Turning ratio = n2/n1=20
primary volt=12v
sec. volt=?

n2/n1=v2/v1
20=v2/12
v2=240v

Vidhya said: (Jan 11, 2011)  
K=N2/N1=V2/V1
20=V2/12
V2=12*20
V2=240V

Nani said: (Jan 27, 2011)  
Given ,k=20 (k=turns ratio)
and primary AC voltage is 12v,

We have to find secondary voltage=?,
as we know that, turns ratio=k=N2/N1,
K=N2/N1=20
(SECONDARY VOLTAGE/PRIMARY VOLTAGE)=v2/v1=v2/12,
THEREFORE,
N2/N1=V2/V1,
20=V2/12
V2=20*12=240

Kunal said: (Feb 9, 2011)  
In transformer

t1/t2=v2/v1

20=v2/12,

v2=20*12=240

Sandhya S said: (May 5, 2011)  
vs/vp=20
vs/12=20
vs=20*12
vs=240

Jodagay said: (Jun 11, 2011)  
Very simple::.

20*12=240.

Pinnapareddy.Sandhya Lakshmi said: (Jun 27, 2011)  
v2/v1=n2/n1=k
here k=20,v1=12v
v2/12=20
v2=240v

Nikhilesh said: (Aug 9, 2011)  
v2/v1 = n2/n1 = i1/i2 = k (this is standard ratio)
n2/n1 = 20 (given)
20=v2/v1
v2=20*12
=240

Mani said: (Sep 6, 2011)  
E1/E2=N1/N2;
N1/N2=20; so E2=20*12=240volts

Veerendra Singh said: (Sep 25, 2011)  
K(Turning ratio)=V2/V1
V2=20*12
=240v

Sameer Kamble said: (Dec 13, 2011)  
Transformer ratio(K) = n2/n1,v2/v1=20.

So v2/v1 = 240/12 = 20.

Naresh Kumaar said: (Dec 14, 2011)  
Here we have given turn ratio k=n2/n1=20.
primary voltage v1=12v.
secondary voltage v2=?
v2/v1=n2/n1
v2=(n2/n1)v1
v2=20*12=240v

Rupambika said: (Dec 23, 2011)  
Given data

turn ratio k=20

primary voltage v1=12v.

according to the formula

v2/v1= k
=> v2/12v= 20
=> v2= 20*12v
=240v


hence the secondary current is 240v.

AM I RIGHT?

Sundar said: (Jan 23, 2012)  
Turns ratio (N2/N1) = 20 [or] N2/N1 = 20/1

N2 = 20
N1 = 1

V1 = 12V
V2 = ?

Formula: V1/V2 = N1/N2 [or] V2/V1 = N2/N1

Therefore, V2 = V1. (N2/N1)

V2 = 12 x (20) = 240v.

Suvankar said: (Jan 26, 2012)  
Guys, I m confused.
The turns ratio of a transformer is T1/T2=20
Primary turns to the secondary turns is called the turns ratio.
i.e. and E1/E2=T1/T2 [Refer Ashfaq Hussian, Electric machines, page no 3]
The ans should be, E2=E1/20
i.e. E2= 12/20=0.6
Isnt it??

Gayathri.K said: (Jan 27, 2012)  
12*20=240v
secondary voltage = number of turns ratio * voltage in primary
secondary voltage = 12*20
secondary voltage = 240 volts

Khalid Akbar said: (Feb 15, 2012)  
20 Ratio Mean Primary is 1turn and secondary turns are 20
So if secondry voltage is 12 V
So 20*12=240volts

Ramesh said: (Apr 6, 2012)  
Here the given data
N1=20 V1= 12
N2/N1=V2/V1

V2?= n1*vi=20*12=240
N2 ?= n1*v2/n1 =20*240/12=400

Secondary voltage = 240 volts
Secondary turn= = 400t

Pankaj Kumar said: (Apr 14, 2012)  
K=N2/N1=E1/E2
Given that; K=20,E1=12V
20=E2/12
E2=240V

Sadasiva said: (May 7, 2012)  
N2/N1=V2/V1
Here N1=1,N2=20
V1=12;
So V2 = N2*V1
V2 = 20*12
V2 = 240v

Uday said: (Jun 22, 2012)  
V2/V1=N2/N1=I1/I2=K (TURNS RATIO).

SO V2/V1=K.

V2/12=20.

V2=20*12=240V.

Varun said: (Jun 24, 2012)  
V2/V1=N2/N1.

V2/12=20.

V2=20*12=240.

Jitendranath Panda said: (Jun 27, 2012)  
We know,

V1/V2=T1/T2=A2/A1.

Hear T1/T2=20, T1=12,

So V2=12*20=240V.

Krishna said: (Jul 30, 2012)  
Given, k=20 (k=turns ratio).

And primary AC voltage is 12v,

We have to find secondary voltage = ?,
As we know that, turns ratio = k = N2/N1,
K=N2/N1=20.

(SECONDARY VOLTAGE/PRIMARY VOLTAGE) = v2/v1 = v2/12,
THEREFORE,
N2/N1= V2/V1,
20 = V2/12
V2 = 20*12 = 240.

Raki&Amp;Viji said: (Aug 25, 2012)  
Ratio=N2/N1=V2/V1
V2=V1*RATIO
=12*20
=240V

Uma.M said: (Sep 5, 2012)  
We know that k = v2/v1.

Here v1 = primary voltage = 12.

Turns ratio k = 20.

So 20 = v2/12 i.e., v2 = 240v.

Manash said: (Nov 10, 2012)  
We know,

N2/N1=E2/E1=K
According to question
N2/N1=E2/12=20
=>20=E2/12
=>E2=12*20
=240V

Alka said: (Dec 22, 2012)  
k=v2/v1
k=20
v1=12
k=v2/v1
20=v2/12
v2=240v

Parth said: (Jan 5, 2013)  
k = v2/v1; v1 = primary voltage = 12.

Turns ratio k = 20.

So 20 = v2/12 i.e., v2 = 240v.

Praveen Nair said: (Mar 30, 2013)  
N2/N1 = V2/V1 = I1/I2 = Turns ratio.

:. V2 = 20x12 = 240V.

Ravi Chandra said: (Aug 11, 2013)  
n2/n1 = v2/v1.

So n2/n1 is given = 20.

Primary voltage is given = 12v.

Here,
n2/n1 = v2/v1.

20 = v2/12.

v2 = 20*12.

v2 = 240.

Mahesh Bende said: (Aug 18, 2013)  
V1/V2 = N1/N2.

Turns ratio=20 i.e. N2/N1 = 20.

Primary voltage = 12 Volt.

So, Secondary voltage V2 = V1*N2/N1.

= 12*20.

= 240 Volt.

Julymoe said: (Feb 17, 2014)  
Turn = N.

Given, Turn Ratio=N2/N1=20 and Primary voltage=V1=12V.
Secondary voltage=V2=?

According to formula, N2/N1 = V1/V2.
V2 = (N2/N1)V1.
= 20*12.
= 240V.

Ranganath said: (Apr 21, 2014)  
Its simple taking voltage turns ratio: V1/V2 = N1/N2.

Akash.Bhure said: (Apr 29, 2014)  
Solution:

Turns ratio(K) = 20.
Primary voltage = 12.
N2/N1 = V2/V1.
V2 = N2/N1*V1.
V2 = 20*12 = 240V.

Anand said: (Aug 5, 2014)  
n2/n1 = v2/v1.
So n2/n1 is given = 20.

Primary voltage is given = 12v.

Here,

n2/n1 = v2/v1.
20 = v2/12.

v2 = 20*12.
v2 = 240.

Mohammad Talha Mansoor Alvi said: (Aug 17, 2014)  
As N1/N2 = V2/V1.
AND Turns ratio = 20 & V1 = Primary voltage = 12.

While V2=Secondary voltage=? so above equation is used as,
20 = V2/12 &

20*12 = V2 SO V2 = 240V.

Mohan Kumar said: (Nov 4, 2014)  
Turning ratio = n2/n1 = 20 .
Primary volt = 12v.
Sec. volt = ?

n2/n1 = v2/v1.
20 = v2/12.
v2 = 240v.

Abdul Rauf Ansari said: (Dec 20, 2014)  
We know that:

Turn ratio of transformer is define as the ratio of turns of the wire in the primary winding to the number of turns of the wire in secondary winding.

i.e Turn ratio = N1/N2.

Given: N1/N2 = 20.

Primary side voltage V1= 12 volt.

Secondary voltage V2 = ?

Hence according to voltage transformation ratio.

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

Or, V2/V1 = N2/N1.
Or, V2 = N2/N1*V1.

= 1/20*12.
= 0.6 volt.

Jatin said: (Jan 6, 2015)  
Yes 0.6 is the right answer because we must follow the transformation rule. That is n1/n2=v1/v2=i2/i1=k.

Than 240 is wrong answer.

Lauren said: (Jan 14, 2015)  
On my research:

Turn Ratio = Vpri/Vsec = Npri/Nsec.

Transformation Ratio = Vsec/Vpri.

Please verify the formula.

Nirupam said: (Jan 30, 2015)  
Turn ratio = T1/T2, this is always put in order input : output, which is primary : secondary.

And T1/T2 = V1/V2 = 20.

Or, 12/V2 = 20.

Hence V2 = 12/20 = 0.6 volt.

Kiran .,Suresh said: (Feb 9, 2015)  
Given that N2/N1 = 20.

V1 = 12.
V2/V1 = N2/N1 = 20.

So V2 = 20*V1.
= 20*12.
= 240.

Prem Prakash Knit Sultanpur said: (Apr 18, 2015)  
v1/v2 =1/k.
12/v2 = 1/20.
v2 = 240v.

Deepak said: (May 9, 2015)  
0.6 is the correct answers.

Because turns ration is (v1/v2) = (t1/t2) and it is given (t1/t2) = 20 and v1 = 12. So the answer v2 = (12/20).

Mahmoud said: (Jun 2, 2015)  
n1/n2 = v1/v2.
20 = 12/v2.
v2 = 12/20 = 0.6 v.

Anand said: (Aug 5, 2015)  
Actually turn ratio of transformer is given by n1/n2.

Therefore if turn ratio is 20 then the answer is 12/20. There is some mistake in the question.

Mac Francis said: (Aug 25, 2015)  
VS/VP = TS/TP.
VS = VP*20.

VS = 12*20.
VS = 120 V.

Er. Vikash said: (Sep 29, 2015)  
If you don't know the correct answer. Please don't explain. There is a mistake in options.

Above most of given explanation that is wrong correct answer is V1/V2 = E1/E2 = Turn ratio.

i.e 12/v2 = 20 so v2 = 12/20 = 0.6.

Prasenjit Patra said: (Oct 3, 2015)  
V2/V1 = K;

So V2/12 = 20 then V2 = 240 (answer) where v2 is secondary voltage, v1 is primary voltage, k is transformer ratio.

Sharad Pawar said: (Jan 28, 2016)  
Turns ratio is means N1/N2 and transformation ratio is N2/N1 but here turns ratio is given 20.

It means N1/N2 = 20. And primary voltage (V1) = 12 V.

Also, N1/N2 = V1/V2.

So, 20/1 = 12/V2.

Hence V2 = 0.6 V.

Dkp said: (May 22, 2016)  
Turns ratio a = v1/v2 = e1/e2 = t1/t2.

where a = 20, v1 = 12.
Substitute the value
20 = 12/v2.

Then, v2 = 12/20 = 0.6v => Answer.

G Shiva Kumar said: (Jun 13, 2016)  
K = E2/E1 = V2/V1 = R2/R1 = I1/I2.

SO, K = SECONDARY VOLTAGE VALUE/PRIMARY VOLTAGE VALUE.

K = V2/V1.
Given data:
K = 20.
V1 = 12 VOLTS.
V2 = ?

K = V2/V1.
20 = V2/12.

V2 = 20*12 = 240A.

Kalendra said: (Jun 24, 2016)  
Very simple.

v2 = v1*turn ratio.
So, the answer is 240 V.

Shujaa Rheem said: (Oct 14, 2016)  
The correct answer 0.6 not 240 because the turn ratio high so n1 high that lead the transformer step_down.

So the secondary voltage less than from the primary n1/n1 = 20 that represent simple k then k = v1/v2 then 20 = 12/v2 so v2 = 12/20 = 0.6.

Jyoti said: (Nov 22, 2016)  
Ans.is 0.6.

Because Turns ratio for the transformer is N1/N2.And It's already given in data.
Now, when we calculate the secondary voltage by transformation ratio. Then it will become

N2/N1 = V2/V1,
1/20 = V2/12,
V2 = 12/20,
V2 = 0.6 volts.

According to me, the options are wrong.

Abhishek Chandra Jha said: (Nov 30, 2016)  
Answer is 0.6. The turns ratio is N1/N2 not N2/N1.

Sam said: (Dec 22, 2016)  
K=N2/N1= V2/V1 no of turns ratio is 20, primary voltage 12 due to which V2 = 20x12 = 240 Volt.

Veena said: (Jan 29, 2017)  
Turns ratio= 1/k.
So 1/k = v1/v2.
20 =12/v2,
v2 = 12/20,
v2 =0.6v.

So, Options are wrong.

P.Rajesh said: (Mar 11, 2017)  
How to identify sum in take primary turn or a Secondary turn? digit.

Sai said: (Feb 15, 2018)  
You are correct @Veena. I agree with you.

Instructor said: (Apr 18, 2018)  
Anyone that got 240 volts for a secondary voltage is incorrect.

The correct answer should 0.6 volts.The reason being is that the equation for turns ratio is (N1/N2)=(V1/V2). We are given (N1/N2) - our turns ratio - to be 20 and V1 is 12. So, 20=12/V2, therefore, V2 is 0.6.

Vicky said: (Apr 22, 2019)  
Turn ratio = N1/N1=20.
Transformation ratio = V2/V1 = N2/N1.
i.e, V2/V1= 1/20.
V2 = 12/20,
V2 = 0.6 .

Biswajit Barik said: (Sep 8, 2019)  
No, the right answer is 0.6V in case of the ideal transformer if we assume permeability is infinite in ideal transformer then in case of ideal transformer in loaded condition N1I1=N2I2so in that condition we say I1/I2=N2/N1=1/a so that but practical transformer with finite permeability then this relation not valid because of I=Inot+I2.

Here transformation ration only practical transformer is E1/E2=N1/N2.

Lalita said: (Mar 4, 2020)  
Some are saying that 0.6 is the right answer, But it's wrong. the right answer is 240.

E2/E1 = V2/V1 = N2/N1 = K.
N2/N1 = 20.

V1 = 12.
So, 20 = V2/V1.

20 = V2/12.
20*12 = V2.
V2 = 240.

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