PHEP 24 Flashcards
(31 cards)
What are the most important functions performed by batteries?
-portable source of power -source of emergency power -stored energy source -Pure source of DC
What is the basic unit of a battery?
The cell
When a higher voltage is needed that one battery can provide, additional batteries can be connected in?
series
How can you obtain more current than one battery can be produced?
By connecting additional batteries in parallel
What are the polarity of the electrodes within a battery?
The anode is positive. The cathode is negative.
The potential between the two electrodes of a cell depends almost entirely on?
The materials in the plates and the electrolyte
Standard cells are not used as a source of __________. They are used for?
Energy, Checking very sensitive laboratory instruments.
What is the most widely used cell in modern storeage batteries?
The lead cell
What is the electrolyte in a lead acid battery?
Sulphuric acid diluted with pure water
What are the active parts of the plates in a lead cell?
Lead peroxide and sponge lead electrolyte is sulfuric acid
During their chemical reaction what do the components of a lead cell create?
lead sulphate
What is the open circuit voltage of a fully charged commercial lead cell?
2.07
What happens when the voltage and specific gravity curves level off while charging takes place?
gassing rises
How do you prevent violent bubbling when charging?
By reducing charging current
What is formed during battery discharge?
Lead Sulphate
Describe cathodic protection
positive lead grounded, negative lead attached to pipe
Control bus batteries are used to supply electrical power to: A) Operate oil circuit breakers B) Emergency Pumps C) Emergency lighting systems D) All of the above
D) All of the above
A dry cell is? A) a secondary cell B) Polarized cell C) Primary cell D) Voltaic cell
C) Primary cell
One essential difference between primary and secondary cells lies in the fact that? A) A primary cell can be recharged B) A primary cell is always larger C) A secondary cell produces less power D) A seconday cell can be recharged
D) A secondary cell can be recharged
The plates of a lead acid battery are made of? A) Lead and lead peroxide B) Peroxide and lead sulfate C) Lead and lead dioxide D) Lead and Lead oxide
A) Lead and Lead peroxide
A battery is receiving a normal charge. It begins to gas freely. The charging current should? A) be increased B) be decreased C) be cut off and the battery allowed to cool D) remain the same
B) Be Decreased
The number of negative plates in a lead-acid cell is? A) one greater than the number of positive plates B) equal to the number of positive plates C) One less than the number of positive plates D) Double the number of positive plates
A) One greater than the number of positive plates
A battery hydrometer reading is 1.206 at 92°F the correct reading is? A) 1.211 B) 1.201 C) 1.221 D) 1.191
A) 1.211 +0.001 (points) for every 3° above 77°F -0.001 (points) for every 3° below 77°F 92°-77°=15° of change 15°/3=5 points (5 points x 0.001)+1.206
The floating charge of a bettery refers to? A) the change given when the hydrometer bulb floats on the electrolyte B) the charge that is given periodically C) the charging rate in amps when the current just balances the current required by the external load plus the internal losses of the battery D) the floating charge of icons in the electrolyte
C) the charging rate in amps when the current just balances the current required by the external load plus the internal losses of the battery
