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# Heater Effect on Bulb

If Heater of 1000W is connected in series with 60 W bulb. what is the effect on the bulb.
Asked by: Rahulshelke | Member Since Jul-2010 | Asked on: Jul 12th, 2010
Showing Answers 1 - 5 of 5 Answers
raviiisc

Answered On : Jul 14th, 2010

View all answers by raviiisc

As we are taking voltage as constant, the total power rating gets increased so the current also gets increased. The bulb filament may not bear that much current because it is rated to 60W.

As the blub filament is broken mechanically so one more thing the heater also does not work. Hence no current through the heater due to open circuit at the bulb.

3 Users have rated as useful.

SURAJTHEGREAT

Answered On : Jul 16th, 2010

Power=V(square)/R...

So,for a constant voltage,the resistance value is finite

If voltage is 230Volts,R=5.29ohms...

Since already the bulb has an resistance,now since the heater and bulb connected in series the net resistance increases considerably and hence current is reduced only to an extent.

An hence bulb glows slightly dimmer but no major effect on bulb due to 10000W heater

1 User has rated as useful.

om_zzz

Answered On : Aug 9th, 2010

View all answers by om_zzz

If voltage is 220V than current rating of bulb = 60/220 = 0.272amp (from ohm`s law) and resistance of bulb = 220*220/60 = 806.6 ohm.

For heater current = 1000/220 = 4.54 amp
and resistance = 220*220/1000 = 48.4 ohm

If both are connected in series on same voltage,
I mean 220 volts then
Total load = 806.6+48.4 =855 ohm.
Circuit current = 220/855 = 0.257 amp

Here circuit current is less than bulb rating so if both are connected in series than bulb will glow with dim light but heater
will not heat up.

sharath2088

Answered On : Jan 7th, 2011

View all answers by sharath2088

The bulb will get burnt only when there is more current flowing into it than rated current. Addition of another resistance in series will lead to addition of resistances and hence should result in a drop in the voltage across either one of them, ie less than rated voltage. So either will not do their function. The bulb wont light, the heater wont heat

bittu123

Answered On : Nov 9th, 2011

@ om_zzz

You are right, bulb will glow but dimmer and heater will not heat-up(more precisely it will generate very less heat)

SURAJTHEGREAT

Answered On : May 5th, 2012

1 Thing everybody has to remember is that only current and not the voltage remains constant across the elements.Let us assume that the elements in series are connected to 220V supply source.
Total power to be supplied is 1000+60=1060W.
VI=1060..therfore current is 4.8A.This is the current that is flowing across both the elements.(heater as well as bulb).I^2/R=1000...resistance of heater=43.4ohms.Similarly resistance of bulb is 2.6ohms.
voltage across heater=208.32V
voltage across bulb=11.68V
So if the voltage rating of both the elements are 220V,bulb will be glowing very dim and heater would not work as expected!!!

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