MCQs on Power Systems

01․ Pelton turbine is a ----------- turbine

Pelton turbine -----> Impulsive turbine Francis turbine -----> Inward radial flow turbine Kaplan turbine -----> Axial flow turbine

02․ Based on the discharge, Kaplan turbine will discharge

Turbines classification based on discharge: 1. High discharge (>10000 lpm) ----> Kaplan turbine 2. Medium discharge (<10000 and >1000 lpm) ----> Francis turbine 3. Low discharge (<1000 lpm) -----> Pelton turbine Where lpm = litres per minute

03․ Which of the following is low specific speed turbine?

Turbines classification based on specific speed: 1. High speed (>300 rpm) ----> Kaplan turbine 2. Medium speed (<300 and >60 rpm) ----> Francis turbine 3. A)Low speed (<60 and >30 rpm) -----> Pelton turbine with multi jets B)Low speed (<30 rpm)----> Pelton turbine with single jet

04․ Which of the following is low specific speed turbine?

Turbines classification based on specific speed: 1. High speed (>300 rpm) ----> Kaplan turbine 2. Medium speed (<300 and >60 rpm) ----> Francis turbine 3. A)Low speed (<60 and >30 rpm) -----> Pelton turbine with multi jets B)Low speed (<30 rpm)----> Pelton turbine with single jet

05․ For variable heads of near about but less than 30 meters, which type of turbine is used in hydro power station?

Turbines classification based on head: 1. High head (>300 meters) ----> Pelton wheel turbine 2. Medium head (<300 and >30 meters) ----> Francis turbine 3. Low head (<30 meters) -----> Kaplan turbine

06․ More efficient plants are used as

A base load power plant is a power station that usually provides a continuous supply of electricity throughout the year with some minimum power generation requirement. Base load power plants will only be turned off during periodic maintenance, upgrading, overhaul or service. Base load power plant has the character of slow demand respond, a mechanism to match generation with the load it supplies. A peaking power plant is a power station that only runs during high demands of electricity throughout the day during peak hours. Because of that, the price of electricity it generates is generally higher than the electricity generated by base load power plant, which operates continuously throughout the year.

07․ Major share of power produced in India is through

Approximate share of power produced in India: Thermal plants --- 70% Hydro plants ------ 20% Nuclear plants ---- 7% Gas, diesel and other non conventional plants ---- 3%

08․ More efficient plants are used as

A base load power plant is a power station that usually provides a continuous supply of electricity throughout the year with some minimum power generation requirement. Base load power plants will only be turned off during periodic maintenance, upgrading, overhaul or service. Base load power plant has the character of slow demand respond, a mechanism to match generation with the load it supplies. A peaking power plant is a power station that only runs during high demands of electricity throughout the day during peak hours. Because of that, the price of electricity it generates is generally higher than the electricity generated by base load power plant, which operates continuously throughout the year.

09․ The method of neutral grounding affects the

System grounding refers to the electrical connection between the phase conductors and ground . Different types of groundings are 1. Resistance grounding 2. Reactance grounding 3. Solid grounding 4. Isolated grounding These methods of groundings affects the zero sequence network only.

10․ Find the value of a⁷²⁹, where "a" is the operator

For reducing the number of vectors and to get the relation between the vectors operator "a" is used. Operator "a" rotates a vector in anticlock wise direction. a = 1∠ 120° a² = 1∠ 240° = 1∠ -120° a³ = 1∠ 360° = 1 a⁷²⁹ = (a³)²⁴³ = 1∠ -120°