Related InterviewSolutions

• If the per unit leakage impedance for the primary of a transformer is ‘x’ on the given rated base value. If the voltage and volt-amperes are halved, then the changed per unit impedance will be ___________(a) 0.5x(b) 2x(c) 4x(d) xThis question was addressed to me during a job interview.The query is from Voltage Regulation of Transformer topic in chapter Transformers of Electrical Machines
• The voltage regulation fortransformer is given by ___________(a) (E2-V2)/E2(b) (E2-V2)/V2(c) (V2-E2)/E2(d) (V2-E2)/V2The question was posed to me in semester exam.I need to ask this question from Voltage Regulation of Transformer in section Transformers of Electrical Machines
• Two tranformer having same voltage but different KVA are operating in parallel. For a good load sharing __________(a) impedance must be equal(b) pu impedances must be equal(c) pu impedance and X/R ratios must be equal(d) impedance and X/R ratios must be equalThis question was posed to me during an internship interview.I need to ask this question from Autotransformers topic in division Transformers of Electrical Machines
• When a transformer winding suffers a short circuit, then inter turns of the same winding experience ______ forces.(a) an attractive(b) a repulsive(c) no force(d) may be attractive or repulsive typeThe question was posed to me in an internship interview.This interesting question is from Autotransformers in portion Transformers of Electrical Machines
• In a transformer, we place the tapping windings at the middle because __________(a) of radial forces on the windings(b) axial forces on the windings(c) insulation level of the winding(d) to provide a mechanical balance to the windingsI got this question during an interview for a job.I'm obligated to ask this question of Autotransformers in portion Transformers of Electrical Machines
• The tappings on the transformers is provided on __________(a) h.v side at one end of the winding(b) l.v. side at one end of the winding(c) h.v side at middle(d) l.v side at middleI had been asked this question in my homework.My question is based upon Autotransformers topic in section Transformers of Electrical Machines
• If a transformer is at no load, then it will act like __________(a) a resistor at p.f = 0(b) an inductive reactor at 0.2 lagging(c) a capacitive reactor at0.2 leading(d) an inductive reactor at 0.8 laggingThe question was asked in examination.The above asked question is from Autotransformers in section Transformers of Electrical Machines
• A 1-phase tranformer has a leakage impedance of 1+ j4 Ω for primary and 3+ j11 Ω for secondary windings. This transformer has __________(a) H.V primary(b) Medium voltage primary(c) L.V primary(d) L.V secondaryI got this question in an international level competition.This is a very interesting question from Autotransformers topic in chapter Transformers of Electrical Machines
• Maximum efficiency of a transformer for a constant load current, occurs at __________(a) at any p.f(b) zero p.f leading(c) zero p.f lagging(d) unity p.fThis question was addressed to me during an interview for a job.My question comes from Autotransformers topic in chapter Transformers of Electrical Machines
• Three transformers having identical dimensions but with core of iron, aluminium and wood are wound with same number of turns and have same supply. Then choose the order for eddy current losses.(a) wood > aluminium > iron(b) aluminium > iron > wood(c) iron > wood > aluminium(d) iron > aluminium > woodThe question was asked in a national level competition.My question is taken from Autotransformers topic in portion Transformers of Electrical Machines