Generation Of Electricity Flashcards
What depends on the operation of photocells?
Light intensity, the kind of light and the depletion layer
How many volts from a photocell per cm square?
0.6v and a power of approx 10milli watts
What does a thermocouple do?
Used to measure the temperature using electricity
What kind of thermocouple is mostly used in engines?
Chromel and alumel
What happens in a chemical reaction to generate electricity
Two metals eg. Zinc and copper are immersed in a conducting liquid eg. Sulphuric acid to get a charge
What is a primary cell
Non rechargeable battery
What is a secondary cell battery
Rechargeable battery
What is usually used in a secondary cell battery
Usually is nickel cadmium or leaf acid in aircraft
What are some advantages of a nickel cadmium battery over lead acid?
- Better power to weight ratio
- Closed circuit voltage remains almost constant throughout discharge
- Larger capacity
What are disadvantages of nickel cadmium batteries
More costly
Larger
What makes up a nickel cadmium battery ?
The positive plate is impregnated with nickel oxyhydroxide and the negative plate is metallic cadmium. The electrolyte is potassium hydroxide.
What depends on the current draw of a battery
The size of the plates
What is a lead acid battery made of?
lead acid cell consists of positive plates filled with lead peroxide (PbO2), negative plates filled with pure spongy lead (Pb) and a liquid electrolyte consisting of sulphuric acid (30%) and water (70%
What does a generator do?
Separates the charge
