a bulb of 100W and anather bulb of 200W , rated supply
voltage 230v.when supply voltage is reduced to 100v,which
bulb will give more light? and why with calculation?

Answer Posted / nitin

p=v^2/r
now in both cases whtevr the voltage ,it is same for both
bulbs.
now the main culprit is r,the bulb which has more
resistance would glow dimmer as per above formula.
we have used the above formula bcaz ,elctrcl instruments
are designd for constant voltage.
as power is inversely proportonal to the resistance (above
formula)therefor 200w bulb would have less resistance and
glow more

Is This Answer Correct ?    13 Yes 6 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Explain the working of any one cutting machine

662


what is the practical application of full adder circuit?

1416


Is it possible to operate a synchronous 2-poles turbogenerator with a still-in-place faulted bar but electrically disconnected ???? If yes, should I act on the other phases as well ???

1446


1. Can a 12v DC choke operate a 60v/12w PL lamp ? 2. Can a 230v ballast fire / operate a 60v/12w PL lamps.

1762


What is the high series capacitance winding on high voltage power transformer ?

1609






what is the breaking capacity and making capacity of circuit breaker and how

1591


What is Percentage impedence of a transformer? why it is expressed at a percentage? what is the importance of percentage impedence in case of a transformer?

1432


if any house we instaled a 1.5 ton ac and its phase cable of wiring is installed but netrual cable of wiring not instaed. my question is that is neutual of house(for other wiring is capable for ac load or a sepeart neutrual wiring required

1968


what are the dimensions for 200 kva transformer plinth (plateform),in which pcc m20 is used..

10773


take 100kva DTR( delta/wye ), what ll happen if we connect 11kv to LT side instead of connecting to HT side? will the DTR behave as a step up transformer or something else????

1812


Pl.brief me about Electrical power distribution system from Main generating station to Industry.What is the use of in between station.

1592


why impudance relay used for medium transmission power system? why not others?

916


how we can calculate chiller required ampear?

1593


What is the criteria that generally follow by distribution licenses to fix contact demand of their industrial customers?

1106


what is meant by tranformer impedance?

2156