ELECTROLYSIS AND STORAGE BATTERIES

The lead acid accumulator should be recharged when the specific gravity of the electrolyte is about A. 1.15 B. 1.80 C. 1.25 D. 1.35

A. 1.15

When n cells, each of emf E volts, and internal resistance r ohms are connected in parallel, the strength of the current is given by A. E/(R + r/n) B. nE/(r + R) C. E/(n + Rr) D. E/(R + n/r)

A. E/(R + r/n)

One advantage of a secondary cell is that it A. can be recharged B. can be used for portable equipment C. it is compact, easy to carry D. cannot be recharged

A. can be recharged

Gassing occurs in the process of A. charging an accumulator B. charging a dry cell C. discharging an accumulator D. discharging a dry cell

A. charging an accumulator

The function of the depolarizer in carbon zinc cell is that A. it converts the produced hydrogen into water B. it prevents the fast chemical action on the zinc container C. it synthesizes the decomposed electrolyte D. it absorbs the oxygen produced in the cell

A. it converts the produced hydrogen into water

Which of the following acts as depolarizer in dry cell? A. manganese dioxide B. zinc chloride C. ammonium chloride D. carbon powder

A. manganese dioxide

Which of the following is a primary cell A. mercury oxide B. lead-acid C. nickel-iron-alkaline D. nickel-cadmium-alkaline

A. mercury oxide

Distilled or approved water is used in electrolytes because it A. prevents or slows down local action B. speeds up electrochemical action C. improves specific gravity D. prevents polarization

A. prevents or slows down local action

Secondary cell large amounts of power for a A. short time and can be recharged B. long time and can be recharged C. short time and cannot be recharged D. long time and cannot be recharged

A. short time and can be recharged

Charging a lead-acid cell causes the electrolyte to become A. stronger B. stable C. weaker D. water

A. stronger

The average dry cell gives an approximate voltage of A. 1.3 V B. 1.5 V C. 1.1 V D. 1.7 V

B. 1.5 V

Local action in the primary cell can be rectified by A. charging the cell B. amalgamating the zinc electrode with mercury C. using the cell for just few minutes D. dry cel

B. amalgamating the zinc electrode with mercury

In electroplating, the positive electrode is called A. cathode B. anode C. terminal D. iontrap

B. anode

The action of a dry cell is to change A. chemical action to mechanical energy B. chemical action to electrical energy C. electrical energy into mechanical energy D. electrical energy into magnetic energy

B. chemical action to electrical energy

Polarization in dry cell can be got rid by A. coating the electrodes of the cell B. chemical means C. discharging the cell D. disposing the cell

B. chemical means

Cells are connected in series to A. decrease the voltage output B. increase the voltage output C. decrease the internal resistance D. increase the current capacity

B. increase the voltage output

The advantage of the iron-nickel over the lead-acid battery is that A. it has much higher efficiency B. it needs less maintenance C. the cell voltage of the iron-nickel battery is higher D. it is much cheaper

B. it needs less maintenance

The two main defects of the primary cell are A. polarization and sulphination B. local action and polarization C. buckling and polarization D. sulphination and buckling

B. local action and polarization

Electrochemical equivalent is A. ratio of atomic weight of an element to atomic weight of hydrogen B. mass of the element liberated per unit quantity of hydrogen C. ratio of atomic weight of valency D. none of the above

B. mass of the element liberated per unit quantity of hydrogen

It is not desirable to leave a lead storage battery in a discharged state for a long time mainly because A. electrolyte will attack the container B. plates will become sulphated C. electrolyte will become weak D. acid will evaporate

B. plates will become sulphated

The condition of a liquid electrolyte is measured in terms of its A. current value B. specific gravity C. acid content D. voltage output

B. specific gravity

Electrolyte of a strong battery is formed by adding A. water to hydrochloric acid B. sulphuric acid to water C. hydrochloric acid to water D. water to sulphuric acid

B. sulphuric acid to water

The ampere hour capacity of battery depends on A. the thickness of the plates B. the area of the plates C. the strength of the electrolytes D. the distance between the plates

B. the area of the plates

When the electrolyte of a storage battery is low it is usually proper to A. add a special weak acid solution B. top up with distilled water C. charge the battery for a short time before adding an electrolyte D. drain battery completely and fill it with fresh electrolyte

B. top up with distilled water

A fuel cell converts ___ energy into electrical energy. A. mechanical B. magnetic C. chemical D. solar

C. chemical

When n cells, each of emf E volts, and internal resistance r ohms are connected in series, the current i through an external resistance R ohms is given by A. i = E/(R + r/n) B. i = E/(R + n) C. i = nE/(R + nr) D. i = E/(r + nR)

C. i = nE/(R + nr)

Cells are connected in parallel to A. increases the internal resistance B. decrease the current capacity C. increase the current capacity D. increase the voltage output

C. increase the current capacity

Nickel-cadmium dry cell is becoming popular in power supplies to electronic calculators because A. it has standard shape B. it is dry C. it is rechargeable D. it is easily manufactured

C. it is rechargeable

While charging accumulators, one should A. check the acid level with a lighted match B. short cells to see if they are full charged C. keep them in a well-ventilated space D. connect and disconnect them with the supply on

C. keep them in a well-ventilated space

The composition of a secondary cell is A. zinc, copper and dilute sulphuric acid B. zinc, carbon and dilute sulphuric acid C. lead, lead peroxide and dilute sulphuric acid D. zinc, copper dilute boric acid

C. lead, lead peroxide and dilute sulphuric acid

Impurities in an electrolyte can cause an internal short circuit condition called A. depolarization B. electrolysis C. local action D. polarization

C. local action

A cell which is used as voltage reference source for instrument calibration is A. solar cell B. dry cell C. mercury-cadmium cell D. nickel-cadmium cell

C. mercury-cadmium cell

The internal resistance of a discharged battery compared with a charged one A. is more B. is less C. remains the same D. is negative

C. remains the same

Separators in storage battery cell are designed to prevent plates from A. touching the electrolyte B. touching the container C. shorting together D. shorting to the sediment

C. shorting together

One factor affecting voltages of the primary cell is the A. area of the plates B. distance between the plates C. types of plates and electrolyte D. thickness of the plates

C. types of plates and electrolyte

To obtain a high voltage of about 1.9 V from a dry cell, one would use A. Western standard cell B. Leclanche cell C. Nickel cadmium cell D. Magnesium cell

D. Magnesium cell

Which of the following affects the capacity of a lead-acid battery? A. temperature B. discharge time C. specific gravity D. all of these

D. all of these

To keep the terminals of a lead acid storage battery free from corrosion, it is advisable to A. clean the terminals frequently B. charge for the battery at frequent intervals C. keep the electrolyte level low D. apply petroleum jelly

D. apply petroleum jelly

A partially discharged lead storage battery may be brought back to full charge by A. adding sulphuric acid B. adding distilled water C. applying ac voltage across the terminals D. applying dc voltage across the terminals

D. applying dc voltage across the terminals

The mass of an ion liberated at an electrode is directly proportional to the quantity of electricity which passes through the electrolyte. The above statement is associated with A. Gauss's theorem B. Laplace law C. Weber and Erwing's theory D. laws of electrolysis

D. laws of electrolysis

Other types of accumulators besides the lead acid type are A. alkaline batteries only B. alkaline and solar batteries C. alkaline and dry batteries D. nickel-cadmium batteries

D. nickel-cadmium batteries

The mass of material deposited over an electrode is A. proportional to voltage B. proportional to time only C. proportional to current only D. proportional to quantity of electricity and electrochemical equivalent

D. proportional to quantity of electricity and electrochemical equivalent

The condition of a secondary cell can be determined by A. its terminal voltage B. the color of the electrolyte C. the level of the electrolyte D. the terminal voltage and strength of the electrolyte

D. the terminal voltage and strength of the electrolyte

During the charging period of a lead-acid battery, the charging rate is lowered to prevent violent gassing because A. the gasses given off are explosive B. evaporation of the electrolyte will weaken its effect C. the cells will be subjected to excessive pressure D. violent gassing tends to wash the active material from the plates

D. violent gassing tends to wash the active material from the plates