# Electrical Engineering - Transformers - Discussion

### Discussion :: Transformers - General Questions (Q.No.19)

19.

To step 120 V ac up to 900 V ac, the turns ratio must be

 [A]. 75 [B]. 750 [C]. 7.5 [D]. 0.13

Explanation:

No answer description available for this question.

 Abby Joseph said: (Dec 15, 2010) N2/N1=K=V2/V1 Here V1 is 120, V2 is 900 so K=900/120=7.5

 Ahmed Al Rawas said: (May 20, 2011) Why shouldn't be N1/N2 = v1/v2 thus, N1/N2 = 120/900 = .133 isn't that right ??

 Ambrish said: (Jul 7, 2011) Yeah my doubt is also same ?

 Murugaperumal said: (Aug 10, 2011) It is step up transformer so, N2/N1=V2/V1, N2/N1=900/120, N2/N1=7.5.

 Pruthvi said: (Aug 15, 2011) Is turns ratio different for step up and step down transformer?

 Mahijagadeesh said: (Sep 2, 2011) Turns ratio means the ratio of primary turns to secondary turns is it wrong? But why in this problem took reverse.

 Yogesh Sabota said: (Nov 4, 2011) I agree with Mahijagadeesh this answer is incorrect It should be 0.13v

 Asim Juneja said: (Jan 22, 2012) N2/N1 is transformation ratio while, N1/n2 is turns ratio, thus my perception says correct ans. is 0.13

 Mahesh Pakki said: (Mar 26, 2012) Guys ... please remeber for step down transformer , turns ratio < 0 Step up transformer , turns ratio > 0 .. In this question .. its step up .. hence turns ratio should be greater then zero ..

 Sirisha said: (May 24, 2012) Turns ratio=N1/N2. (step down). Turns ratio=N2/N1. (step up). If not mentioned the type of tx by default consider step up.

 Amarjyoti Sarmah said: (Aug 15, 2013) Is turns ratio different for step up and step down transformer? N2/N1 is transformation ratio while, N1/N2 is turns ratio, Is not it right. I am very much confused. Please help me?

 Naveed said: (Oct 20, 2013) The ratio of a four-to-one step-down transformer is written as 4:1.The ratio of a one-to-four step-up transformer should be written as 1:4. Notice in the two ratios that the value of the primary winding is always stated first.

 Rajan India said: (Mar 16, 2015) Turns ratio k = v2/v1. Here, k = Turns ratio of transformer. v2 = Secondary voltage of transformer. v1 = Primary voltage of transformer.

 Vicky said: (Jan 3, 2016) Turns ratio means ratio of high voltage side to low voltage side turns.

 Stuti Kushwaha said: (Feb 16, 2016) Please help me that where we can use n1/n2 and where we can use n2/n1?

 Mehaboob Nadaf said: (Mar 20, 2016) N2/N1 = V2/V1. 900/120 = K=7.5.

 San said: (Mar 24, 2016) Is it same for V2/V1, R2/R1 & I1/I2?

 Raghuvamsi said: (Apr 29, 2016) Yes, @Ahmed. The answer should be 0.13. Here the problem is asking turns ratio, not transformation ratio.

 Ramesh said: (Jun 16, 2016) Finally, what is the correct answer?

 Ajit said: (Nov 22, 2016) Yes, I agree the answer is 0.13.

 Sanjay Patil said: (Nov 24, 2016) Yes, Agree with the answer 0.13. Because N2/N1= V2/V1= I1/I2 it is transformation ratio and N1/N2 is Turn Ratio.

 Teja said: (Jun 20, 2017) Turns ratio is primary to secondary. So the answer is wrong.

 Aditya Singh said: (Apr 14, 2018) Yes, the answer should be 0.13.

 Ankita Mali said: (Dec 23, 2018) What is the final answer? Please tell me.

 Shivam said: (Sep 29, 2019) Answer will be 0.13. Because turn ratio is inverse of transformation ratio.

 Sayan Paul said: (Nov 2, 2020) 0.133.

 Abhinaya said: (Apr 15, 2021) I agree with 0.13 the 7.5 is k. Turns ratio = 1/K, 1/7.5 = 0.13.

 Srinivas Reddy said: (Jul 5, 2021) To step up by means N2/N1 high voltage to low and step down N1/N2.