A lamp can work on a 50 volt mains taking 2 amps.what value of the resistance must be connected in series with it so that it can be operated from 200 volt mains giving the same power.
Answers
Answered by
5
Power of lamp, P = VI = 50 volts X 2 Amperes = 100 watt
since, P = V² /R
Here, P = 100 watt
V = 200 volts
R = ?
So, 100 = (200) /R²
R = 400 ohms
since, P = V² /R
Here, P = 100 watt
V = 200 volts
R = ?
So, 100 = (200) /R²
R = 400 ohms
anustarnoor:
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V=50v I=2A. V=IR 50=2R R=25ohm P=V2R. 50*2*25 =2500/25 = 100W P=40000/R'. 100=40000/R' R'=400 R'=R+R' ,, 400=25+R'. R'=375ohms
see this solution is currect or wrong !?
this is wrong because if u apply ohms law by putting 375 ohms it will not verify ohms law but if u put 400 ohms then ohms law will be valid and voltage will be 209V
sorry 200V
ooh... Thankuh
no problem
Answered by
2
As power is same
so,
P1=P2
V1I1=V2I2
I2 = 0.5 amp
By OHM'S LAW
V =RI
R = 200/0.5
R = 400 ohms
so,
P1=P2
V1I1=V2I2
I2 = 0.5 amp
By OHM'S LAW
V =RI
R = 200/0.5
R = 400 ohms
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