14. The output current corresponding to maximum efficiency for a transformerhaving core loss of 100 W and equivalent resistance referred to secondary of 0.2:is .. ampere.(a)20(b)25(c)5(d) 40015. At relatively light loads, transformer efficiency is low because(a) secondary output is low(b) transformer losses are high(c) fixed loss is high in proportion to the output(d) Cu loss is small.16. When a 400-Hz transformer is operated at 50HZ its kVA rating is(a) reduced to 1/8(b) increased 8 times(c) unaffected(d) increased 64 times.17. The voltage applied to the h.v. side of a transformer during short-circuit test iof its rated voltage. The core loss will be..percent of the rated core loss.(a)4(b) 0.4(c)0.25(d)0.0418. The main purpose of performing open-circuit test on a transformer is to measits(a) Cu loss(b) core loss(c) total loss(d) both Cu and total losses.19. During short-circuit test, the iron loss of a transformer is negligible because(a) the entire input is just sufficient to meet Cu losses only(b) flux produced is a small fraction of the normal flux(c) iron core becomes fully saturated(d) supply frequency is held constant.20. A transformer has negative voltage regulation when its load power factor is(a) zero(b) unity(c) leading(d) lagging.

18). The main purpose of performing open circuit test is to measure iron losses or core losses.…

19. During short-circuit test, the iron loss of a transformer is negligible because (a) the entire input is just sufficient to meet Cu losses only (b) flux produced is a small fraction of the normal flux (c) iron core becomes fully saturated (d) supply frequency is held constant. 20. A transformer has negative voltage regulation when its load power factor is (a) zero (b) unity (c) leading (d) lagging.

19. During short-circuit test, the iron loss of a transformer is negligible because (a) the entire input is just sufficient to meet Cu losses only (b) flux produced is a small fraction of the normal flux (c) iron core becomes fully saturated (d) supply frequency is held constant. 20. A transformer has negative voltage regulation when its load power factor is (a) zero (b) unity (c) leading (d) lagging.

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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