MCQs

High frequency transformer usually employes: Copper core Cast iron core Air core Mild steel core Correct answer: 3. Air core

The main cause of harmonics produced in a transformer: Core saturation Poor insulation Fluctuating load Mechanical vibrations Correct answer: 1. Core saturation

Buchholz relay can be installed on: Air-cooled transformers Oil cooled transformers Auto-transformers All of these Correct answer: 2. Oil cooled transformers

The correct statement about moisture contents in a transformer: There should be 50% moisture There should be 70% moisture gases There should be no moisture There should be  95% moisture contents Correct answer: 3. There should be no moisture

Distribution transformers should be designed to have maximum efficiency at: Full load No load 50% to 60% of load 95% to 96% of load Correct answer: 3. 50% to 60% of load Explanation: The distribution transformer is designed to work with maximum efficiency at 50% to 60% of the load. Because normally doesn’t it is … Read more

The transformer working is based on the principle of _________ inductance, between two ___________ coupled coils: Self, Capacitive Self, Inductively Mutual, Capacitive Mutual, Inductively Correct answer: 4. Mutual, Inductively

Function of Breather in transformer is to: Absorb moisture Allow dry air to go in Both of these None of these Correct answer: 3. Both of these The transformer breather uses Silica Gel. Silica gel has character of being chemically inert, posses high surface area, and has high internal porosity. It has very strong adsorption … Read more