Catalog of Electrical Engineering questions with useful answers that help you develop a clear insight of your conceptual problems.
List of topics:
Question: What is minimum firing angle for three-phase thyristor? Answer: The minimum firing angle for three-phase thyristor is 30 degrees. Because under that angle the thyristor is already reverse biased by the third thyristor that is already conducting. If firing angle is between 0 to 30 the circuit works in continuous conduction mode. Reference: Other Basic … Read more
Question: Why transformer rating is expressed in kVA instead of kW or kVAR? Answer: At the time of manufacturing, the nature of load to be connected is not known. (i.e it is resistive, reactive, R, RL, RC, RLC or of any other type). Therefore it is beneficial to express power in terms of voltage and … Read more
Switchgear is often classified on the basis of voltage level for which it is designed. 3 Types of switchgear in this regard are: LV Switchgear – Rated for voltage under 1 kV MV Switchgear – Rated for voltage under 36 kV HV Switchgear – Rated for voltage above 36 kV Other PSP Questions: Justify the … Read more
Question: What do you mean by switchgear? Answer: The equipment used for switching, controlling, protecting, and isolating electronic equipment. The Electrical Switchgear is a generic term that represents all components and equipment which is involved in: Control Protection Isolation Must read: LV Switchgear components List of components in switchgear: Annunciator Bus bar Circuit breaker Control … Read more
The transformer is an electrical device which steps up and steps down the ac voltages. Given below are top 10 transformer questions for electrical engineering interviews. Question 1: Why short circuit test is performed on transformers? Answer: The short circuit test is performed for calculating the copper losses. Question 2: Why open circuit test is … Read more
Question: Explain the classification of hydroelectric power plants on the basis of head? OR Question: How many types of dams are there on the basis of head height? Answer: On the basis of the head the dams are divided into three classes. Type Head Low head < 30 m Medium head 30-100 m High head … Read more
The term hydroelectric power refers to the generation of electricity by utilizing the potential energy of water. Hydroelectric power is a renewable energy source with a net energy production of 4000 TWh. How does it work? The water is stored in a reservoir at a certain height (head). Water flows down through the pipes and hits the turbines … Read more
The energy which is produced from the motion of tides. The tidal energy is classified as the renewable energy source. How is it utilized? The gravitational pull of sun and moon produces tides. A tidal barrage is constructed which utilizes the potential energy generated by the change in height between high and low tides. Is it … Read more
Question: Why ac is used for mains electricity? Answer: Alternating current is used in mains because most of the power components require AC. AC Motors are common in air conditioners, washing machines, water pumps, juicer machines, ceiling fans, room coolers. Electronic equipment like mobile phones, laptop chargers utilize dc power. Modern inverters and compressors also rely on … Read more
Question: When and Why do multiple conductors per phase are used in the transmission lines? Answer: Multiple conductors are used when transmission voltages are above 345 kV. Technically the term bundled conductors are used for representing two, three or more conductors per phase. Generally, two, three, or four conductors are used for 345, 500, and … Read more