Objective Question on Working of Lead Acid Battery

  1. Container of a lead acid battery

    The container of the battery must be mechanically very strong and there should not be any leak. These are all the major things that we are considered while making a battery container. Hence, the above mentioned all the three material can provide the mechanical strength to the container because all the material are basically strong in nature.

  2. Active materials of a lead acid cell are

    The materials which all are participated in the electrochemical charge and discharge reaction are called as active elements of a lead acid cell. These materials include electrolyte and the positive and negative electrodes. We know that the dilute H2SO4 is electrolyte of lead acid cell, the sponge lead is negative electrode and the lead peroxide is the positive electrode. Hence, all of the above are active materials of a lead acid cell.

  3. Which cell has the reversible chemical reaction?

    A chemical reaction that can be reversed to its original state after it has reacted is called reversible chemical reaction. It happens only in Lead acid cells because mercury oxide, silver oxide and carbon zinc cells cannot recharge again. Once the cell dried that’s it and even if we connect with an external voltage source these cells cannot do any reaction. But, in the lead acid cells, once the cell has completely dried then if we give an external supply voltage, it reacts again and at the full charged condition it achieves the initial state. This is how we have differentiated the cells into primary and secondary types.

  4. The life of a lead acid battery is expected to be

    The life of a lead acid battery is calculated in terms of charging / discharging cycles. The lead acid battery provides approximately 200 to 300 charging / discharging cycles. Also the life is short due to grid corrosion on the positive plate and a low voltage limit subjects to sulfation on the negative plate. Hence, the life of a lead acid battery is approximately in between 2 to 5 years.

  5. The capacity of a lead acid cell does not depends on its

    The rate of charge is used to denote that how fast the battery is getting charged and then the capacity is expressed in ampere-hours (AH) is the product of the electric current discharged and the duration of discharging time at a particular temperature. If the quantity of the active materials is more, then the capacity of the cell is more. Hence, the capacity of a lead acid cell does not depend on its rate of charge.

  6. Fillers in a lead acid battery are provided

    Lead-acid battery can produce explosive mixtures of hydrogen and oxygen gases when they are being charged. If ventilation is poor, the escaping hydrogen creates an explosive atmosphere around the battery. Always keep sparks, flames, burning cigarettes and other sources of ignition away from the battery recharging area because the gas can be ignited. The result of an explosion could be severe burns and/or fire. Hence, the filters in a lead acid battery are provided to facilitate the flow of gases.

  7. The term trickle charge is associated with

    If we want to charge the lead acid battery, the constant voltage charging method is suitable. The trickle charging is one of a constant voltage charging system and that means charging a fully charged battery under no load at a rate which is equal to its self discharge rate. This can enable the battery to remain at fully charged level. That is why the trickle charging system is associated with lead acid battery. The silver zinc and nickel iron battery need a constant current source to charge them. The dry cell is a primary battery and that cannot be reused again.

  8. A 6 V lead acid battery has an internal resistance of 0.01 Ω. How much electric current will flow when the battery is short circuited?

    In a battery , the short circuit electric current is the ratio of battery voltage to the internal resistance. Hence, Isc = 6 / 0.01 = 600 Amps.

  9. In a lead acid cell, hydrogen is liberated at

    During the charging process, the battery cell cannot absorb all of the energy from the charging electric current supply. Through electrolysis principle, excess energy breaks down the water and it creates the hydrogen and oxygen gasses. The oxygen is liberated at the positive plates and the hydrogen at the negative.

  10. The lead acid cell should not never be discharged beyond

    Rather than a 100 percent depth of discharge, we have to charge the battery at 80 percent depth of discharge. The meaning is that only 80 percent of the available energy is being delivered and 20 percent remains in reserve. This kind of discharge method increases service life of the battery. The fully charged lead acid cell has 2.25 Volts. The 80% of this voltage is nearly to 1.8 Volts.

  11. The watt-hour efficiency of a lead acid cell varies between

    Normally lead acid battery are having the watt-hour efficiency between 70 to 80%.

  12. The internal resistance of lead acid cell is _______________ that of Edison cell.

    The Edison cell is nothing but the nickel battery. In the nickel battery, the positive and negative plates are in the form of nickel plated steel tubes that filled with Ni(OH)4. Due to the presence of nickel, it increases the internal resistance of the cell because the nickel has higher resistance in nature.

  13. When the lead acid cell is fully charged the electrolyte assumes ________________________ appearance.

    During the fully charged condition, the electrolyte produces hydrogen and oxygen gases. Due to the formation of hydrogen bubbles in the electrolyte, it gives the electrolyte a milky appearance.

  14. The ratio of ampere-hour efficiency to watt-hour efficiency of a lead acid cell is

    In watt hour efficiency, we are considered the voltage and current. The discharging voltage is always less than the charging voltage. We know that, the watt hour efficiency is the ratio of the product of discharging voltage and discharging electric current to the product of charging voltage and charging current. Thus, the overall watt hour efficiency is always less than the ampere hour efficiency.

  15. Open circuit voltage of a fully charged lead acid cell is

    In a new lead acid battery, under equalizing charge the voltage rises to approximately 2.65 to 2.7 volts per cell.

  16. In a lead acid cell PbSO4 formed during

    When a lead-acid battery is discharged, the electrolyte divides into H2 and SO4. The H2 will combine with some of the oxygen and that is formed on the positive plate to produce water (H2O). The sulfate (SO4) combines with the lead (Pb) of both plates, forming lead sulphate (PbSO4).

  17. During charging, the electrolyte of a lead acid battery becomes

    During the charging process, the amount of acid content in the electrolyte increases and that makes the electrolyte as stronger.

  18. The value of specific gravity of acid when a lead acid battery is fully charged is

    In a fully charged cell, the electrolyte has a specific gravity that varies from 1.260 to 1.285 and it depends on the type and the manufacturer.

  19. The electric current flowing between electrodes inside a lead acid battery is

    In lead acid battery, the gas evolution rates at both electrodes are increased due to the float polarization. Hence, the electric current flowing between the electrodes inside the battery is polarization current.

  20. The plates of lead acid storage battery are most likely to be short circuited if

    During charging and discharging, the lead on the plates gets gradually eaten away and the sediment falls to the bottom. This lead sediment is a conductive material and that makes a short circuit in between the positive and negative plates and finally it becomes a full short circuit.