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The correct choice is (a) Air conditioning

The best I can explain: For cooling, the heat from the battery can be dissipated only through the air conditioning CIRCUIT. The battery heat from the refrigerant circuit of the air conditioning system can be transferred,using CONDITIONED air,a DEDICATED COOLANT circuit.

Right choice is (c) 60

The explanation: Lithium-ion BATTERIES should not be stored at temperatures above 60 degrees centigrade and OPERATED at above 40 degrees centigrade. LIKEWISE there is an appreciable REDUCTION in the potential charging and discharging rate below -5 degrees centigrade.

Correct answer is (c) Aluminum foils coated with graphite metal oxide

The best explanation: The LITHIUM-ion batteries having round Li-ion CELLS employ ANODE of aluminum foils coated with graphite and cathodes of copper foils coated with lithium metal oxide. The wound ELECTRODES are soaked with an organic ELECTROLYTE.

The correct answer is (b) 100-265

Explanation: Lithium-ion battery has a PROMISING FUTURE as a rechargeable battery for the electric hybrid vehicle due to its very high storage capacity,which ranges from 100-265 watt-hour per KG with the fact that it operates at room TEMPERATURE.

The correct choice is (B) ALUMINUM foil coated with graphite

Best EXPLANATION: The Lithium-ion battery having round Li-ion cells employ ANODES of aluminum foils coated with graphite and is soaked with an organic electrolyte, which ENABLES the transfer of lithium ions in the first place.

Right option is (d) Lithium carbide

Explanation: During the charging PROCESS, lithium ions are released from the METAL oxide and MOVE through the separator to the graphite electrode where lithium carbide is formed. The ENERGY stored in the charging process can be released again by the inverse chemical REACTION.

Right choice is (d) High energy DENSITY

The BEST I can explain: The disadvantages of a lithium-ion BATTERY are it is more EXPENSIVE,SINCE these are more complex to manufacture. These require a sophisticated charger to carefully monitor the charging process which makes it more complex. Whereas high energy density is the advantage of the lithium-ion battery.

Right choice is (b) Opposite direction of current

The best EXPLANATION: During the charging mechanism of lithium-ion BATTERY the current flows from the anode to the cathode whereas the electrons PRESENT in the cathode MOVE from cathode to anode thus the movement of the electrons is opposite when compared to the direction of current flow.

Correct answer is (b) Lithium-based gel

Easiest explanation: Lithium-ion batteries also work by shuttling IONS between the electrode. During charging, ions travel in ONE direction; during the discharging process, they GO in the other direction. The electrolyte is a lithium-based gel or polymer.

The CORRECT choice is (c) Rapid discharging

The explanation: The BATTERY which is not excessive sulphates can be recharged keeping the charging RATE LOW. The precautions to avoid sulphation are the battery water LEVEL should be checked, and the electrolyte level and gravity level should be maintained at the proper value and heavy discharge of battery should be avoided.

Right choice is (d) Overcharging

The best I can explain: The main TROUBLE a faces is bulged case which because of overcharging of the BATTERY to avoid overcharging the regulated VOLTAGE must be REDUCED. And the clamps should not be too tight and the TEMPERATURE of the battery should be maintained.

Correct answer is (a) Separator

For explanation: The internal short-circuiting is caused by either damaged SEPARATORS or when the active MATERIAL dropping from the PLATE FORMS itself into a heap so HIGH as to cause short-circuiting. It results in rapid self-discharge and sulphation.

The CORRECT CHOICE is (B) PLATES are disintegrating

Easiest explanation: Discolouring of electrolyte is one of the battery troubles. The discolouring of the electrolyte is an indication that the plates are disintegrating and the battery has almost EXHAUSTED its life.

Right answer is (a) Lead-acid

The best I can explain: In the lead-cadmium grid battery does not require any WATER to be added during NORMAL service, as excessive water loss may be caused due to higher than normal CHARGING rate due to incorrect SETTING of the REGULATOR.

The correct option is (b) INTERNAL RESISTANCE

Explanation: Large lead sulphate crystals, whitish in colour are formed on the plates. These crystals are difficult to be converted back into ACTIVE materials on recharging. Sulphation of the battery reduces the CAPACITY and increases the internal resistance of the cells.

The correct choice is (d) STRATIFICATION

The explanation is: Stratification is one of the battery TROUBLES. Long term storage of the battery causes stratification of the electrolyte, for example, the BOTTOM layer becomes heavier than the top layers. Such stratification sets up LOCAL equalising currents which INCREASE the self-discharge rate.

The correct option is (d) Use of distilled water for electrolyte

To explain I WOULD say: The main cause for self-discharging of the battery are contamination of the electrolyte, DAMAGED SEPARATORS and long TIME storage. By USING pure sulphuric acid and distilled water for preparing electrolyte helps in the life of the battery.

Correct answer is (c) 10

To elaborate: CELL gravity VARIATION is one among the other BATTERY troubles during the cell gravity variation the gravity READINGS of all the cells should be the same. If the reading of some cells is different from the rest by more than 10 gravity POINTS, it indicates the loss of acid from a cell.

Correct option is (c) To avoid the damage of the separator and plates

The best I can explain: The WATER in the electrolyte keeps on evaporating and periodic CHECKS must be made to ENSURE that proper level and gravity is being maintained. If this is not done, the SEPARATORS and the plate MAY be permanently damaged.

Right OPTION is (c) Liquid ammonia

To explain: Due to OXIDATION the battery TERMINALS and the clamp MUST be cleaned after regular intervals. After cleaning with a cloth moistened with liquid ammonia, a coat of petroleum jelly helps to RETARD their corrosion again.

The correct OPTION is (d) Discolouring of electrolyte

The best explanation: The factors affecting the charging of a battery are temperature, area of the plate, STATE of charge, gassing, IMPURITIES, corrosion of TERMINAL, and clamps whereas the discoloring of the electrolyte has no EFFECT of charging of the battery.

The correct option is (d) Engine speed

The explanation is: METALLIC particle on insulator tip, ERODED ELECTRODE indicates that the plug as running overheated this MAY arise due to weak MIXTURE, defective cooling system, loose-fitting causing the exhaust gases to leak.

The correct answer is (C) 20

For explanation I would say: Twenty-minute rate of a BATTERY represents the rate of current a battery can deliver continuously for 20 minutes, the cell voltage not dropping below 1.5. The TEMPERATURE of the battery at the start of the test is brought to 80 degrees.

Correct option is (c) Hydrogen and oxygen

For EXPLANATION I would say: The major FACTOR AFFECTING the charging is GASSING wherein excessive hydrogen and oxygen BUBBLES due to overcharging may wash away active material on the plates, decreasing the charging rate. Due to which overcharging must be avoided.

The correct ANSWER is (C) DECREASE

The explanation: The important factor affecting the CHARGING rate is the impurities present in an electrolyte. The electrolyte impurities decrease the charging rate. Apart from the impurities, gassing ALSO decreases the charging rate of the battery.

The correct option is (a) COLD-CRANKING amperes

For explanation I would say: The ABBREVIATION of CCA is cold cranking amperes. The CCA rating of an automobile BATTERY must equal or exceed the number of CUBIC inches of engine displacement. The temperature of the cold rate or CCA of the battery at the beginning of discharge is kept -18 degrees centigrade.

Right answer is (c) 12-20

Easiest explanation: The battery generally takes from 12-20 hours for RECHARGING a battery DEPENDING upon the condition of the battery and the charging rate. However, BATTERIES with sulfate plates require low charging CURRENT and hence longer time FOE charging.

Correct answer is (a) Spilled electrolyte

The explanation is: The corrosion of TERMINALS and CLAMPS is one of the major factors affecting charging. Due to spilled electrolyte and condensation from GASES the internal resistance of the BATTERY increases resulting in a decrease in the charging rate.

The correct option is (a) Ebonite tube

Explanation: The hydrometer is in the form of a glass tubular body with a rubber BULB at the top and a SAMPLER tube at the bottom. There is a glass float inside the glass body. This float has a vertical density SCALE. Whereas the ebonite tube in USE encloses the cadmium rod in the cadmium test.

Correct answer is (a) Generator

For explanation I would say: A generator is provided so that it can constantly charge the battery. The rate of charging CURRENT FLOWING from the generator to the battery depends upon the state of charge of the battery. If the battery is run down, the charging rate will be HIGHER, and as it gradually charged the rate TAPERS off to LOWER value.

The CORRECT option is (a) Not more than 0.2

For explanation: In a cadmium test the CHEMICAL CONDITION of the POSITIVE and negative plates is determined. The reading with the negative battery terminal should not be more than 0.2 volts when the battery is being DISCHARGED at a normal rate. A higher reading in this case will indicate defects in negative plates.

The correct choice is (d) Specific gravity test

Explanation: Specific gravity test is the only test where a voltmeter is not used INSTEAD of a voltmeter a hydrometer is used to DETERMINE the specific gravity of the electrolyte. The float inside the hydrometer rises and then the read off the scale at the SURFACE level of the sample DRAWN in.

The correct choice is (B) 1.29

To explain I would say: The specific gravity in MANY cases is used to find the state of the battery. The specific gravity for a fully charged battery is 1.29 and along with this reading the temperature is also noted accordingly and then compared with the CHART SUPPLIED by the battery MANUFACTURER.

Right choice is (a) Should not be LESS than 2.5

Easy explanation: In a cadmium test the CHEMICAL CONDITION of the positive and negative plate is found.In the case of a positive terminal, the voltage READING should not be less than 2.5 volts if the battery is nearing completion of its charge or 2.0 volts if the battery is being DISCHARGED at a normal rate.

Correct option is (c) Fully charged state

The BEST explanation: A high discharge test is MADE for 10-15 min at the END of which the voltage should not fall below 1.5 volts and the difference of cell voltage of VARIOUS cells should not EXCEED 0.2 volts and this test should be made only on fully charged or at least on half-fully charged batteries.

The CORRECT answer is (a) The voltage of cell=Specific GRAVITY +.840

Best explanation: In an open volt test a change of 0.01 volt of open-circuit voltage is equivalent to a change of 0.010 in the specific gravity of the ELECTROLYTE. The relationship between the open-circuit voltage of a battery and its specific gravity is Voltage of the cell =specific gravity +.840.

The CORRECT option is (c) 15

To EXPLAIN: A high discharge test is CONDUCTED with the help of a cell voltage tester wherein the voltmeter is connected to two legs with a high resistance placed across them. This test should not be made continuously for more than 15 seconds otherwise the battery plates will GET permanently damaged.

Right choice is (b) Cadmium test

To EXPLAIN: The cadmium test is conducted to know the chemical condition of the positive and NEGATIVE plates and is performed only when the battery is either on charge or discharge. In the case of the positive TERMINAL the voltage reading should not be less than 2.5 volts and in case of the negative battery,the terminal should not be more than 0.2 volts.

Correct option is (b) Voltmeter

To elaborate: In the OPEN volt test the STATE of charge is determined. The open-circuit voltage of a battery CELL is measured with the HELP of an ordinary voltmeter. The open-circuit voltage of a FULLY charged battery cell is about 2.1 volts.

Right option is (c) Allow the diffusion of acid

To elaborate: The material of the SEPARATOR, apart from being non CONDUCTING, must be sufficiently porous or PERFORATED to allow diffusion of the acid. The separator must be slightly thinner than space into which they fit.