21
|
Why some voltage drop occurs in the cell?
|
|
The voltage drop occurs in the cell due to the resistance of the
electrodes, electrolyte and contact resistance between electrolyte and
electrodes.
|
22
|
Why it must be necessary to keep emf of all cells are equal when they
are connected in parallel?
|
|
If the emf of the cells is not equal, circulating current flows which
will cause unequal loading on the cells.
|
23
|
How the individual cells are connected in order to achieve higher
voltage, higher rating cell is required?
|
|
Cells connection
- The cells are connected in the mixed grouping in order to achieve
higher voltage, higher current rating.
- There are few cells connected in series in branch and such branches are
connected in parallel in this method.
|
24
|
Explain the following terms : Ampere hour capacity and Watt hour
capacity
|
|
Ampere hour capacity
- The ratio of the output ampere hour during discharging to the input
ampere – hours during charging of cell is called as ampere-hour capacity.
Watt hour capacity
- The ratio of the output watt-hours during discharging to the input
watt – hours during charging is called as watt – hour capacity of the cell.
|
25
|
State the different methods used for charging batteries.
|
|
The followings are the methods used for charging batteries:
- Constant voltage charging
- Constant current charging
|
26
|
Explain the following terms : Boosting charging , Float charging and Trickle
charging.
|
|
Boosting charging
- When the charging of cell is done at high current rate, it is called
as boosting charging.
Float charging
- The cell is charged and discharged simultaneously in the railway
compartments. This is called as float charging.
Trickle charging
- When the charging of cell is done at continuous low current rate, it
is called as trickle charging.
|
27
|
What is meaning of gassing in the cell?
|
|
Gassing
- The hydrogen at the cathode and oxygen at the anode terminal produces
after fully charging of the cell. This process is called as gassing.
|
28
|
State the Faraday’s law of electrolysis.
|
|
Faraday’s first law
- It states that the mass of iron liberated at an electrode is directly
proportional to the quantity of electricity passed through it.
Faraday’s second law
- It states that when the same quantity of electricity is passed through
several substances, the mass of substance deposited on its directly
proportional to chemical equivalent weight.
|
29
|
State the unit of Electro chemical equivalent of the substance.
|
|
Unit of E.C.E.
- According to Faraday’s first law
m α Q
m = ZQ
- Where Z is called as electro chemical equivalent
- The unit of Z is mg / coulomb
|
30
|
Define : Electro chemical equivalent
|
|
Electro chemical equivalent
- It is defined as the mass of ions liberated by the passage of one
ampere current for one second ( or passage of one coulomb charge ) through
electrolyte.
·
Z = m / Q
|
31
|
On which parameter the electro chemical equivalent of the substance
depends?
|
|
Electro – chemical equivalent
- The Electro chemical equivalent of any substance depends upon the
atomic weight, valency of an ion and Faraday’s constant.
|
32
|
Explain the term : Faraday’s constant
|
|
Faraday’s constant
- It is defined as the charge required for liberating one gram
equivalent of substance.
OR
- It is ratio of the chemical equivalent to electrochemical equivalent
of a substance. It is equal to 96,500 coulomb.
|
33
|
Define : Chemical equivalent
|
|
Chemical equivalent
- It is defined as the ratio of atomic weight to the valency of
substance.
|
34
|
State the unit of Faraday’s constant.
|
|
The unit of Faraday’s constant is coulomb.
|
35
|
Explain the term : Back emf or Polarization
|
|
Back emf
- It is opposing emf produced in an electrolyte due to absorption of
gaseous ions by the electrolyte from electrodes.
|
36
|
Define : Decompose voltage
|
|
Decompose voltage
- It is defined as the minimum voltage requires decomposing an
electrolyte.
|
37
|
Which electrode potential is taken as reference potential for
calculating potential of an electrode?
|
|
Hydrogen electrode
|
38
|
Write the full form of SLI batteries.
|
|
The SLI stands for starting, lighting and ignition batteries.
|
39
|
Which are the main parts of any cell?
|
|
Parts of cell
- Positive plate
- Negative plate
- Separator
- Electrolyte
|
40
|
Classify the different types of cell.
|
|
Types of cell
- Automotive or SLI cell
- Vehicle traction cell
- Stationary cell
|
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