Sources of Electricity

What is the main purpose of a hydroelectric dam?

• To store drinking water

• To generate electricity

• To prevent flooding

• To irrigate farmlands

What part of the dam channels the high-pressure water to the turbines?

• Draft tube

• Generator

• Penstock

• Reservoir

What converts the mechanical energy from the turbines into electrical energy?

• Transformer

• Draft tube

• Substation

• Generator

What do geothermal energy plants primarily harness to generate electricity?

• The energy of falling water

• The heat energy within the earth

• The power of the wind

• The energy from the sun

What equipment do geothermal plants use to access underground heat?

• Solar panels and batteries

• Wells and pumps

• Turbines and generators

• Windmills and blades

What is thermoelectricity?

• Electricity generated by flowing water

• Electricity generated by sunlight

• Electricity generated by applying heat to the junction of two dissimilar materials

• Electricity generated by chemical reactions

What happens when one end of the joined wires is maintained at a higher temperature than the other?

• The wires melt

• A voltage difference arises

• The wires stop conducting electricity

• The materials change into magnets

In a photoelectric cell, what initiates the flow of electrons?

• Chemical reaction

• Photoelectric emission

• Heat energy

• Magnetic fields

What happens when pressure is applied to certain crystals?

• They generate heat

• They generate light

• A potential difference develops across them

• They become magnetic

What is the electricity produced by applying pressure to crystals called?

• Photoelectricity

• Thermoelectricity

• Piezoelectricity

• Hydroelectricity