when 40 watts and 60 watts bulb is connected in series,
which bulb glows brightly ?
Answer Posted / syed golam kibria
'V' across both the bulbs will be the same...
we have,
P=V^2/R;
R=V^2/P;
so calculating resistances,
R60=240*240/60=960ohm,
R40=240*240/40=1440ohm,
Req=(960*1440)/(960+1440)=576ohm,
Total current through the circuit:
240/576=0.625A
current through the 40W bulb,
0.25A
current through the 60W bulb,
0.375A
Now,
E=i^2*r*t
E40=0.25*0.25*1440*t=90t
E60=0.375*0.375*960*t=135t
for a same time period 't'...60W bulb dissipates more energy...
so the 60W bulb glows brightly...
Is This Answer Correct ? | 4 Yes | 27 No |
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