1.
During the Charging of Lead-acid cell:
Correct Answer
A. Its voltage increases
Explanation
During the charging of a lead-acid cell, the voltage increases. This is because the charging process involves the conversion of electrical energy into chemical energy, which is stored in the cell. As more and more energy is transferred to the cell, the voltage across the terminals increases. This is an important characteristic of the charging process and indicates that the cell is being replenished and prepared for future use.
2.
In a lead-acid battery, .................................. is used as an electrolyte.
Correct Answer
D. Diluted sulpHuric acid
Explanation
In a lead-acid battery, diluted sulphuric acid is used as an electrolyte. This is because sulphuric acid is a strong acid that can dissociate into ions in water, allowing for the flow of electric current. By diluting the sulphuric acid, it reduces the concentration of the acid, making it safer to handle and reducing the risk of corrosion. Additionally, the diluted sulphuric acid provides the necessary ions for the chemical reactions that occur within the battery, allowing it to generate electrical energy.
3.
The capacity of lead-acid cell does not depends on its:
Correct Answer
B. Rate of charge
Explanation
The capacity of a lead-acid cell is determined by factors such as the quality of the active material, temperature, and rate of discharge. However, the rate of charge does not affect the capacity of the cell. This means that the cell can be charged at a fast or slow rate without impacting its overall capacity.
4.
During the charging process, the specific gravity of the electrolyte of lead-acid battery:
Correct Answer
A. Increases
Explanation
During the charging process of a lead-acid battery, the specific gravity of the electrolyte increases. This is because the charging process involves the conversion of chemical energy into electrical energy, which causes the lead plates in the battery to react with the sulfuric acid in the electrolyte. This reaction results in the formation of lead sulfate and the release of hydrogen gas. As a result, the concentration of sulfuric acid in the electrolyte increases, leading to an increase in the specific gravity of the electrolyte.
5.
In Fully charge condition, Active materials of lead-acid battery are:
Correct Answer
A. Lead and lead peroxide
Explanation
In a fully charged condition, the active materials of a lead-acid battery are lead and lead peroxide. This is because during the charging process, lead sulfate on the negative plate is converted back into lead, while lead dioxide on the positive plate is converted back into lead peroxide. Therefore, the correct answer is lead and lead peroxide.
6.
The capacity of battery is not expresses in terms of:
Correct Answer
C. Voltage rating
Explanation
The capacity of a battery is not expressed in terms of its voltage rating. The voltage rating of a battery refers to the potential difference between its positive and negative terminals. It indicates the amount of electrical pressure the battery can provide. However, the capacity of a battery is typically measured in terms of its ampere-hour rating, CCA rating, or reserve capacity rating. These ratings indicate the amount of charge the battery can store and deliver over a specific period of time.
7.
A dead battery can be revived by:
Correct Answer
D. None of above
Explanation
A dead battery cannot be revived by adding distilled water, electrolyte, or sulphuric acid. These substances are used to maintain the electrolyte levels and acidity in a battery, but they cannot revive a dead battery. When a battery is dead, it means that it has lost its ability to hold a charge and cannot be recharged. In such cases, the only solution is to replace the battery.
8.
Which one of the following is not a battery testing method?
Correct Answer
D. Acidity test of electrolyte
Explanation
The acidity test of electrolyte is not a battery testing method because it does not directly measure the performance or condition of the battery. The acidity test is typically used to determine the level of acid in the electrolyte solution, which can indicate the need for maintenance or replacement of the electrolyte. However, it does not provide information about the battery's capacity, state of charge, or overall health. Other methods like the hydrometer test, open cell voltage test, and cadmium test are commonly used to assess the condition and performance of batteries.
9.
Sulphation in a lead-acid battery occurs due to:
Correct Answer
D. Incomplete charging.
Explanation
Sulphation in a lead-acid battery occurs due to incomplete charging. When a lead-acid battery is not fully charged, lead sulphate crystals can form on the battery plates. These crystals can build up over time and reduce the battery's capacity and performance. Incomplete charging can happen when the battery is not left connected to a charger for a sufficient amount of time or when the charging process is interrupted prematurely.
10.
The electrolyte for a fully charged lead-acid battery
has a relative density of approximately:
Correct Answer
C. 1.280
Explanation
The correct answer is 1.280. The relative density of the electrolyte in a fully charged lead-acid battery is approximately 1.280. This indicates that the electrolyte is denser than water. The density of the electrolyte is important because it affects the battery's performance and ability to store and release energy. A higher density electrolyte allows for a higher concentration of sulfuric acid, which is essential for the battery's chemical reactions.
11.
The essential component of battery ignition system.
Correct Answer
A. Battery
Explanation
The essential component of a battery ignition system is the battery itself. The battery provides the necessary electrical energy to power the ignition system and start the engine. Without a battery, the ignition system would not have the power it needs to generate the spark required to ignite the fuel-air mixture in the engine's cylinders. Therefore, the battery is an indispensable component of the battery ignition system.
12.
Property of material used in ballast resistor is:
Correct Answer
A. It has positive temperature thermal coefficient
Explanation
A material with a positive temperature thermal coefficient means that its resistance increases with an increase in temperature. In the case of a ballast resistor, this property is desirable as it helps to stabilize the current flowing through a circuit by compensating for changes in temperature. As the temperature rises, the resistance of the ballast resistor increases, limiting the current flow and preventing damage to other components in the circuit. Therefore, a ballast resistor having a positive temperature thermal coefficient is the correct answer.
13.
Magneto ignition has a starting problem.
Correct Answer
A. True
Explanation
Magneto ignition systems, which are commonly used in small engines like those found in motorcycles or lawnmowers, can indeed have starting problems. One common issue is a weak or failing magneto coil, which generates the electrical spark needed to ignite the fuel mixture. If the magneto coil is damaged or worn out, it can result in difficulty starting the engine. Other potential causes of starting problems in magneto ignition systems include faulty spark plugs, dirty or clogged fuel filters, or carburetor issues. Therefore, the statement "Magneto ignition has a starting problem" is true.
14.
Ignition coil in battery ignition system _______________________ voltages.
Correct Answer
A. Step-ups
Explanation
In a battery ignition system, the ignition coil is responsible for increasing the low voltage from the battery to a high voltage needed to create a spark in the spark plugs. This process is known as step-up, where the ignition coil steps up the voltage. Therefore, the correct answer is "step-ups".
15.
Function of condenser in battery ignition system is:
Correct Answer
C. To absorb the back e.m.f produce
Explanation
The function of the condenser in a battery ignition system is to absorb the back electromotive force (e.m.f) produced. When the ignition points open, a high voltage spark is generated across the points. This spark creates a sudden surge of current, which generates a high voltage spike known as back e.m.f. The condenser is connected in parallel to the points and acts as a capacitor, absorbing this back e.m.f and preventing damage to the ignition system.
16.
A spark is created as the coil primary winding is:
Correct Answer
A. Switched on
Explanation
When the coil primary winding is switched on, a spark is created. This is because when the circuit is closed, a sudden surge of current flows through the coil. This current generates a magnetic field around the coil, and when the circuit is opened, the collapse of this magnetic field induces a high voltage in the coil. This high voltage can cause a spark to jump across a small gap, resulting in the creation of a spark.
17.
Contact breaker in battery ignition system, breaks the current flowing in secondary winding of ignition coil to stop the spark.
Correct Answer
B. False
Explanation
The contact breaker in a battery ignition system does not break the current flowing in the secondary winding of the ignition coil to stop the spark. Instead, it breaks the primary circuit, which interrupts the flow of current from the battery to the primary winding of the ignition coil. This interruption causes a high voltage to be induced in the secondary winding, creating the spark. Therefore, the given statement is false.
18.
Ballast resistor is connected in parallel with primary winding.
Correct Answer
B. False
Explanation
A ballast resistor is not connected in parallel with the primary winding. Instead, it is connected in series with the primary winding in order to regulate the current flowing through the circuit. By adding resistance in series, the ballast resistor limits the current and prevents damage to the primary winding. Therefore, the correct answer is False.
19.
Spark plug which has short heat transfer path is known as:
Correct Answer
A. Cold plug
Explanation
A spark plug with a short heat transfer path is known as a cold plug. This means that the spark plug is designed to dissipate heat quickly, preventing it from reaching high temperatures. This is typically used in engines that operate at lower temperatures or have high-performance requirements. A cold plug helps prevent pre-ignition or detonation, ensuring optimal engine performance and longevity.
20.
Ignition timing does not depends on:
Correct Answer
C. Piston material
Explanation
Ignition timing refers to the precise moment when the spark plug ignites the air-fuel mixture in the combustion chamber. It is determined by factors such as the compression ratio, engine speed, and mixture strength. However, the material of the piston does not directly affect the ignition timing. While the piston material may have an impact on other aspects of engine performance, it does not play a role in determining the timing of the ignition spark.