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National certificate question from electrotechnology

 

 

Hi,

I'm seeking help on my assessment test of knowledge of EMF production & electrochemistry national certificate in electrotechnology, Level 2. I have completed everything on this test but one thing; can you help?

Complete the following table by identifying for this type of cell. nickel-iron size, nominal voltage, typical capacity, primary, or secondary, common use.

Thanks.

Regards,

Gareth James Maine
Connect Electrical - New Zealand

In the nickel-alkaline cells there are two types- one has nickel-iron based electrodes,the other nickel-cadmium. Both have a operating voltage of 1.2V (1.2V indicates attention is needed). They are used for engine starting, standby power supplies and emergency lighting.The active plate is nickel hydroxide. The negative plate is powered iron held in pockets within a steel frame. The electrolyte is mainly potassium hydroxide in water with additives to lower the internal R of the cell. Correct charging is an important factor in the maintenance of this cell. Testing must be carried out using a high discharge test. A hydrometer cannot be used successfully as a test instrument, as the electrolyte plays no part in the cell's cycle and cannot give an indication of the state of charge.

Jeff Tech
- Australia