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 |
Post New Answer View All Answers
Can an inverter be used as a converter? How?
what is induction furnance? how many phase supply given io its coil for 15 or 20 ton furnance?
What is the Designing & Selection Procedure for a DG/Transormer of rated capacity?
what is the benefit of floating our DC source? if i have two floating DC source of which 1 has a ref voltage of -21VDC and the other of -18VDC. can it be connected in parallel to share a common ref voltage? if not, how do i make both sources to be of common ref voltage? tks
If rotor works in clock wise what happens
Why ground terminal is used in pot meter 10k ohms
How to design inductive load for 3 phase 440v and maximum 5 amps for star or delta? Can we use a 15kW, 1450rpm motor for 15kW, 960rpm apllication?If yes.how......n.if thesame motor used what`s it`s sideeefect.
I am EEE student i want to improve my core side skills.how cn i approach it?
What is the armature mmf in a D.C machine?
how to check ac servo motor
what is acceptance test in electrical engineering.
how r charge carriers produced
What safety precaution are to be taken for avoiding electric hazards ?
how to introduce yourself
What is the principal of motor?