Mechanical Engineering - Automobile Engineering - Discussion


The function of an alternator in an automobile is to

[A]. supply electric power
[B]. convert mechanical energy into electrical energy
[C]. continually recharge the battery
[D]. partly convert engine power into electric power

Answer: Option C


No answer description available for this question.

Niranjan Gupta said: (Mar 9, 2013)  
How alternator recharge the battery?

Velu.S said: (Jul 3, 2013)  
Alternator charges the battery, that's it. It has nothing to do with powering the lights gauges or anything like that. If the alternator is malfunctioning, the battery will eventually die. For most cars manufactured after 1990, if the alternator does not work at all, it could prevent the car from starting.

I hope the answer is correct.

Sabari said: (Jul 11, 2013)  
It is not true. Purpose of battery is to start the engine and restore it energy. While alternator is running after that power from alternator goes to each and every part of engine (not from battery).

Udit Nandy said: (Aug 25, 2013)  
Please explain the difference between Alternator & Dynamo?

Devraj said: (Dec 14, 2013)  
The main propose of alternator. Is Convert mechanical energy into electrical energy. That's it.

Nishar said: (Jan 27, 2014)  
The function of an alternator or a generator is to supply all of the car's electric needs, plus recharge the battery.

A car can run without an alternator or generator, but the battery will eventually go dead.

Johny Kotla said: (Mar 9, 2014)  
The main purpose of alternator is to charge the battery but not continuously.

After completion of charging the battery it will cutoff automatically.

If it charge continuously then the charging voltage will be more than the battery voltage then the heavy voltage produced and repelled to the alternator which cause damage to the alternator.

Giridhara Raam said: (Mar 15, 2014)  
Where exactly is alternator present ?

Ramkrishna Parshuramkar said: (Apr 2, 2014)  
Alternator is basically dynamo working due to force of exhaust gases which charges battery, it is use of exhaust gases inside supercharger.

R K Dixit said: (May 9, 2014)  
No actually the alternator used to recharge the battery and supply the electricity.

Ravindran S said: (May 29, 2014)  
Battery is used to start the engine. Once the engine starts, Alternator takes charge of powering the whole electrical system. One of the functions is charging battery. Hence I would say the correct answer is to "supply electric power" I. E) [A] in the answer sheet.

Partha Roy said: (Jun 6, 2014)  
There is a basic difference between alternator and dinamo 1. Alternator can produce current with a minimum revolution where dinamo need a maximum revolution to produce current. One thing I would like to mention that alternator and dinamo both are produce alternative current. The alternator has three phase and dinamo has two phase. That is the main cause dinamo need more revolution to produce same amount of current related to alternator.

Er. Hemant Gupta said: (Jul 31, 2014)  
Basically alternature convert mechanical energy in AC power, then it will be use in various form like battery charging, light, horn etc & dynamometer use for converting mechanical power in DC Energy.

For another query contact me on my email.

Naveen Thakre said: (Aug 11, 2014)  
Basically alternator use for convert mechanical energy to electrical energy but in automobile function it use only for continuously recharge the battery.

Mahadev said: (Dec 2, 2014)  
@Naveen thakre is right. i.e.. When engine is off battery supplies electricity for lights, horn, etc and also to crank the engine. After engine starts the alternator recharges the battery and supplies power for the electrical load.

Mars said: (Dec 10, 2014)  
When vehicle is in static position, using the electric devices absorb much current. So we say the alternator is meant to convert mechanical energy to electric energy in other to recharge the battery when the engine is start.

Avijit said: (Feb 21, 2015)  
When engine starts the engine covert mechanical energy to electrical energy and storage the power in the battery. And other time the power of the battery distribute the electricity in the engine starts.

Gokula Kannan.T said: (Mar 3, 2015)  
The name itself has that alternate so it well alternately charges the battery.

Seenu Jegan said: (Mar 9, 2015)  
I was using alternator in my project instead of motor then how can you say alternator is used to continually recharge the battery.

Manojkumar said: (May 23, 2015)  
Alternator main function is its convert mechanical energy into electrical energy. Its charging the battery or store the the energy is secondary.

Lalit said: (Jun 17, 2015)  
Alternator is nothing but generator.

Alagu Raja said: (Aug 26, 2015)  
The alternator used only for recharge the battery. That's all.

Selvam Cr said: (Feb 19, 2016)  
An alternator supplies the power to run the vehicle electronics, ignition, lights etc and to charge the battery.

The battery has to deal with a huge power drain when starting. The alternative is a generator.

An alternator is a spinning magnet surrounded by a coil of wire, a generator is usually a magnetic field with a spinning coil of wire.

Mishra Akhilesh said: (Feb 22, 2016)  
But initially it converts mechanical energy to electrical energy, than it helps to recharge battery. So, initial step should be the actual answer.

Dawangave Mangesh said: (Jun 11, 2016)  
The above question answer is D because the alternator is not supplying continuous electrical power to the battery so its cut off the power supply partially by using the cut off the relay.

Milan said: (Jun 15, 2016)  
I agree with Dawangave, the answer is D.

Intzar Ali said: (Jul 18, 2016)  
Alternator: An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature.

Nikky said: (Aug 9, 2016)  
Generally, alternator converts mechanical energy into electrical energy but in question, they asking the use of alternator in an automobile so generally automobile it recharge the battery and along with this it provides electrical energy to the automobile electrical system when engine is running condition. So during vehicle running condition battery does not provide electric power to automobile.

Kpr said: (Aug 21, 2016)  
Alternator used for convert the mechanical energy into electrical energy.

Savan Patel said: (Oct 10, 2016)  
Alternator charge the battery to converting the mechanical energy into electric energy.

Bhargav said: (Oct 19, 2016)  
I think an alternator is nothing but dynamo.

Suman Mondal said: (Oct 24, 2016)  
Alternator recharges the battery and fulfills all the electrical demands when the engine is running.

N.S said: (Apr 16, 2017)  
Alternator is used to convert the mechanical energy in to the electrical energy by using of the crank shaft power.

Suresh Darsi said: (Jun 29, 2017)  
Alternators are used in modern automobiles to charge the battery and to power the electrical system when its engine is running. Until the 1960s, automobiles used DC dynamo generators with commutators.

Vishal Jain said: (Jul 21, 2017)  
But the first alternator converts mechanical to electrical energy then it recharges the battery.

So, I think option B is the correct answer.

Mahesh Nagabhairu said: (Aug 20, 2017)  
Basically, it's just a converter which use engine power and convert that into electrical energy and that in turn leads to the charging of the battery! The principle of the alternator is the rotating magnetic field that generates electricity.

Nikesh G. Deshmukh said: (Dec 13, 2017)  
The answer should be D as the energy input to alternator is mechanical energy as it is rotating on the revolution of shaft and this revolutions (mechanical motion) is transferred to the alternator for the generation of electricity. The supply is takes place by Battery. Answer is right that continuously charging the battery but the basic work of alternator is to change mechanical energy to Electrical.

Rohit Parashar said: (Jan 17, 2018)  
Option C is right but option B is also right because main function of alternator is to convert mechanical energy into electrical energy.

Biswajeet Panigrahi said: (Apr 7, 2018)  
B is correct because first, it converts mechanical energy to electrical energy then it convert ac to dc then it supplies to the battery for storage and uses in Application.

Santhosh said: (Jun 20, 2018)  
The alternator is only converting to mechanical energy convert to electrical energy. Alternator not a full-time charge. Because alternator together fit for the regulator.

Vijay Nokhwal said: (Jun 29, 2018)  
Alternator is also in the genrator its main work is convert mech energy into electrical energy.

Praveentky said: (May 15, 2019)  
Alternators are used in modern automobiles to charge the battery and to power the electrical system when its engine is running.

Until the 1960s, automobiles used DC dynamo generators with commutators.

Seetharaman said: (Sep 13, 2019)  
It's not true. The main function of the alternator and dynamo is converting the engine's mechanical energy to electrical energy.

Lekharaj said: (May 18, 2020)  
Whether the engine is in an off condition. The alternator will supply the power to battery? Tell me anyone.

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