# Electrical Engineering - Transformers - Discussion

### Discussion :: Transformers - General Questions (Q.No.20)

20.

When a 200 load resistor is connected across the secondary winding of a transformer with a turns ratio of 4, the source "sees" a reflective load of

 [A]. 50 [B]. 12.5 [C]. 800 [D]. 0 Explanation:

No answer description available for this question.

 Satish said: (Dec 10, 2010) source sees a reflective load= with respect to primary. Hence, 200/16=12.5 (z/k*k)

 Motiur said: (Dec 16, 2011) As k=rt of r1/r2

 Tarnjeet Singh said: (Jan 6, 2012) Please explain it.

 Vasu said: (Feb 5, 2012) k = sqrt (R/r) 4 = sqrt (200/r) 16 = 200/r r = 12.5

 Raju Saikh said: (Oct 13, 2012) Turns ratio=k= n2/n1 & n2/n1=sqrt(r2/r1) so, k=sqrt(r2/r1) k*k=(r2/r1) here, r2=200ohm;& k=4 so, 4*4=(200/r1) r1=200/16 =12.5

 Rani said: (Sep 7, 2014) What is correct formula to this problem?

 Jagadeesh said: (Dec 13, 2015) Turns ratio k = N1/N2, Transformation ratio K (capital k) = N2/N1. So, K = 1/k. R2' = R2/K^2; Here K = 1/k = 1/4; R2' = 200/(1/4)^2 = 3200, which is not in option.

 Ranjan said: (Apr 22, 2016) How to solve the below problem, can anyone help me? Suppose that two AC waves have the same frequency but differ in phase by exactly 1/20 of a cycle. What is the phase difference between these two waves?

 Shiju said: (Oct 25, 2016) @Jagadeesh answer is very correct explanation. If turns ratio 4 means vp/vs = 4 i.e vp = 4 * vs. If 200 ohm load then vs/200 is the current drawn at secondary So at primary the current Ip will be 1/4 of secondary current = vs/200/4 = vs/800. Then reflective load = Vp/Ip = 48Vs/Vs/800 = 3200.

 Shiju said: (Oct 25, 2016) @Ranjan, I think it will be 18 degrees i.e total 360 degrees so 360/20 = 18.

 Amani Naidu said: (Feb 16, 2017) Clear explanation, Thanks @Jagadeesh. Answer is 3200.

 Ali Butt said: (Aug 4, 2019) R2=R1k^2. R1=R2/k^2. R1=200/(4)^2. R1=200/16. R1=12.5.