1. Which of the following vibrations causes different conductors to touch due to high swing?
a) Aeoline vibrations
b) Galloping vibrations
c) Aeoline and Galloping
d) Amplitude vibrations
Explanation: Galloping vibrations in overhead transmission lines are high amplitude ( about 6 m ) vibrations. During such vibrations conductors ‘dance’ in horizontal and vertical directions with high amplitude which makes the conductors to touch each other.
2. ‘Dancing’ of overhead conductors occurs during which of the following types of vibrations?
a) Aeoline vibrations
b) Galloping vibrations
c) Aeoline and Galloping
d) Amplitude vibrations
Explanation: During galloping vibrations in overhead transmission lines conductors vibrates with high amplitude ( about 6 m ) and low friquency (about 1 or 2 Hz). Swinging of conductors with high amplitudes in horizontal and vertical directions are called as they are ‘dancing’.
3. What are the method for prevention of low frequency high amplitude vibrations?
a) Horizontal conductor configuration
b) Vertical conductor configuration
c) Horizontal and Vertical conductor configuration
d) There is no method for prevention of such vibrations
Explanation: Horizontal conductor configuration can be used to reduce the danger of low frequency vibrations. But no method can prevent such vibrations.
4. What are the methods used to protect conductors against high frequency resonant vibrations?
a) Horizontal conductor configuration
b) Vertical conductor configuration
c) By using dampers
d) There is no method for prevention of such vibrations
Explanation: The conductors are protected by dampers. Dampers prevents the resonant vibrations from reaching the conductors at the clamps or supports.
5. Which of the following power plant causes highest amount of air pollution?
a) Thermal power plant
b) Hydroelectric power plant
c) Nuclear power plant
d) Geothermal power plant
Explanation: The major contribution of electrical power generation is from thermal power plant. The thermal power plant definitely contribute to economic growth but they bring with it like air and water pollution. Thermal power plant mostly causes air pollution by the emission of flue gases into air.
6. Which of the following gas is not emitted during combustion of coal?
a) Oxides of sulphur
b) Oxides of Nitrogen
c) Oxides of Mercury
d) Oxides of carbon
Explanation: Thermal power plant emit large amount of harmful gases such a Sulphur dioxide, nitrogen oxide, CO, CO2, certain hydrocarbons and particulates during the combustion of fossil fuels. There is no any emission of oxides of mercury.
7. Which of the following pollutants emitted by thermal power plant causes irritation in Eyes?
a) Oxides of sulphur
b) Oxides of Nitrogen
c) Oxides of Mercury
d) Oxides of carbon
Explanation: At high temperatures existing in the flame core of high power boilers, the nitrogen of fuel and air may partially be oxidised to form nitrogen oxides. These are toxic and produce a sharp irritating effect especially on the mucous membrane of the eye.
8. Which of the following pollutants emitted by thermal power plant is a cause of global warming?
a) NO
b) CO2
c) SO2
d) NO2
Explanation: Carbon monoxide and carbon dioxide are also emitted during the combustion of coal. Carbon monoxide is very toxic pollutant but it gets converted into carbon dioxide in open atmosphere surrounding the power station. On the other hand carbon dioxide has been identified as major cause of global warming.
9. Which of the following pollutant causes acid rain?
a) NO
b) CO2
c) SO2
d) NO2
Explanation: The Sulphur Dioxide emitted by thermal power plant gradually oxides to sulphur trioxide under the influence of Sunlight. This in turn interact with atmospheric moisture and forms sulphuric acid. This sulphuric acid later causes acid rain.
10. Which of the following is mostly affected by thermal power plant pollutants?
a) Lithosphere
b) Atmosphere
c) Hydrosphere
d) Exosphere
Explanation: The thermal power plant mostly causes air pollution by the emission of harmful flue gases. So, it can be said that thermal power plant mostly pollutes our atmosphere.